500+ TOP Engineering Chemistry MCQs and Answers Quiz

Engineering Chemistry Multiple Choice Questions

1. Select the incorrect statement from the following option.
A. the taste of hard water is better than soft water
B. the dissolved calcium in hard water can help to produce strong teeth
C. hard water coats the lead piping with a layer of insoluble calcium carbonate which prevents poisonous lead dissolving in water
D. boiler feed water should also be hard in nature

Answer: D boiler feed water should also be hard in nature
Explanation: boiler feed water should be free from hardness otherwise explosion may occur. all the other options are correct. the taste of hard water is better than soft water and dissolved calcium in hard water can help to produce strong teeth. hard water coats the

2. Which of the following is not a unit of hardness?
A. parts per million
B. degree centigrade
C. degree clarke
D. degree french

Answer: B degree centigrade
Explanation: degree centigrade is not a unit of hardness. degree centigrade is the unit of temperature. the unit for hardness is ppm (parts per million), degree clarke and degree french. all these three units are inter-related.

3. Hardness of water is conventionally expressed in terms of equivalent amount of
A. h2co3
B. mgco3
C. caco3
D. na2 co3

Answer: C caco3
Explanation: hardness of water is conventionally expressed in terms of equivalent amount of caco3. the total water hardness is the sum of the molar concentrations of ca2+ and mg2+, in mol/l or mmol/l units.

4. Hardness of water is due to the presence of salts of
A. potassium
B. chlorine
C. magnesium
D. boron

Answer: C magnesium
Explanation: hardness of water is due to the presence of salts of calcium and magnesium. hard drinking water may have moderate health benefits, but can pose serious problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling towers, and other equipment that handles water.

5. Select the incorrect statement from the following option.
A. water which does not form lather with soap and forms white scum is called hard water
B. hard water contains dissolved calcium and magnesium salts in it
C. in hard water, cleansing quality of soap is depressed
D. due to the presence of dissolved hardness- producing salts, the boiling point of water is depressed

Answer: D due to the presence of dissolved hardness- producing salts, the boiling point of water is depressed
Explanation: due to the presence of dissolved hardness-producing salts, the boiling point of water is elevated. elevation in boiling point is one of the most important colligative property. all the other options are correct.

6. The chemical equivalent of MgSO4 salt is
A. 10,000
B. 30,000
C. 50,000
D. 70,000

Answer: D 70,000
Explanation: 1 degree clarke = 1 part of caco3 per 70,000 parts of water. it is calculated mathematically.

7. 1 ppm =
A. 0.07 0fr
B. 0.70fr
C. 0.10fr
D. 0.010fr

Answer: C 0.10fr
Explanation: 1 ppm = 0.10fr. it is calculated mathematically.

8. How many grams of MgCO3 dissolved per litre gives 84 ppm hardness?
A. 70.56 mg/l
B. 48.23 mg/l
C. 81.49mg/l
D. 66.12 mg/l

Answer: A 70.56 mg/l
Explanation: 70.56 mg/l of mgco3 dissolved per litre gives 84 ppm hardness.

9. EDTA method for hardness determination is a less accurate and inconvenient procedure.
A. true
B. false

Answer: B false
Explanation: edta method for hardness determination is a more accurate, convenient and rapid procedure. ethylene diaminetetraacetic acid (edta), is an amino poly-carboxylic acid and a colorless, water- soluble solid.

10. Estimation of hardness can be determined by types.
A. 2
B. 3
C. 4
D. 5

Answer: A 2
Explanation: estimation of hardness can be determined by two types. they are soap titration method and edta method.

Engineering Chemistry MCQs

11. Total hardness of water can be determined by titrating the fixed volume of water against the standard solution.
A. soap
B. alkaline soap
C. acidic soap
D. alcoholic soap

Answer: D alcoholic soap
Explanation: total hardness of water can be determined by titrating the fixed volume of water against the standard alcoholic soap solution.

12. The sodium soap will precipitate all the hardness causing ions into their respective
A. carbonates
B. bicarbonates
C. stereates
D. chlorides

Answer: C stereates
Explanation: the sodium soap will precipitate all the hardness causing ions into their respective stereates in the beginning of the soap titration method.

13. The water which form lather directly with the soap is called
A. hard water
B. soft water
C. partially hard water
D. very hard water

Answer: B soft water
Explanation: the water which forms lather directly with the soap is called soft water. the water which forms precipitates when reacted with soap is called as the hard water.

14. EDTA method is also called as
A. complexometric titration
B. complex titration
C. complement titration
D. complexion titration

Answer: A complexometric titration
Explanation: edta method is also called as the complexometric titration. in edta method is ethylene diamine tetra acetate is the compound used to remove the hardness.

15. The indicator used in the EDTA method is
A. benzene
B. phenopthalene
C. ethylene diamine
D. erichrome black t

Answer: D erichrome black t
Explanation: the indicator used in the edta method is erichrome black t. the hardness causing ions like ca++ and mg++ forms the unstable complexes with reacting the erichrome black t.

16. The change in colour is sharper at the PH of
A. 5
B. 10
C. 15
D. 20

Answer: B 10
Explanation: the change in the colour of the ions is sharper at the ph of the 10 than that of the other ranges of the ph.

17. At PH=10, the metal dye complex has the colour
A. wine red
B. blue
C. green
D. pink

Answer: A wine red
Explanation: at the ph=10, the metal dye complex ion has the colour is wine red but the dye itself has the blue colour at the ph of 10.

18. To prepare EDTA solution grams of EDTA is dissolved in the one litre of water.
A. 1
B. 2
C. 3
D. 4

Answer: D 4
Explanation: to prepare edta solution, four grams of the edta is dissolved in the one litre of the water. this is the standard edta solution used to determine the hardness of water.

19. drops of indicator is used in the EDTA method.
A. 1 to 2 drops
B. 2 to 3 drops
C. 2 to 4 drops
D. 5 to 8 drops

Answer: A 1 to 2 drops
Explanation: 1 to 2 drops of the indicator is used in the edta method. 0.5gms of the dye is dissolved into the 100ml of alcohol and the indicator of two to three drops is added.

20. The buffer used in the EDTA solution must have the PH of
A. 20
B. 15
C. 10
D. 5

Answer: C 10
Explanation: the buffer used in the edta solution must have the ph of 10. freshly prepared solutions are more affective to have the accurate results.

21. The standard hard water is prepared such that each ml must contain mg of CaCO3.
A. 1
B. 2
C. 3
D. 4

Answer: A 1
Explanation: the 1g of pure caco3 is dissolved in the minimum amount of concentrated hcl diluted to 1ltr of distilled water such that it contains 1mg of caco3.

22. Water is mainly used in boilers for the generation of
A. power
B. electricity
C. steam
D. current

Answer: C steam
Explanation: water is mainly used in boilers for the generation of steam. this steam is further used in the power plants for the generation of electricity.

23. Which of the following is not a result of the excess of impurity in boiler-feed?
A. scale and sludge formation
B. decomposition
C. corrosion, priming and foaming
D. caustic embrittlement

Answer: B decomposition
Explanation: excess of impurities in boiler- feed results in scale and sludge formation, corrosion, priming, foaming and caustic embrittlement. it does not contribute to the decomposition process.

24. The scales decrease the efficiency of boiler and chances of explosions are also there.
A. true
B. false

Answer: A true
Explanation: the scales decrease the efficiency of boiler and chances of explosions are also there. scale is the precipitate that is hard and adhering on the inner wall.

25. Foaming is caused by the formation of
A. acids
B. alcohols
C. oils and alkalis
D. ketones

Answer: C oils and alkalis
Explanation: foaming is caused by the formation of oils and alkalis. oils and alkalis becomes sticky and greasy on the surface and hence results in foaming.

26. Corrosion is the decay or disintegration of boiler body material either due to chemical or electrochemical reaction with environment.
A. true
B. false

Answer: A true
Explanation: corrosion is the decay or disintegration of boiler body material either due to chemical or electrochemical reaction with environment. it converts a refined metal to a more stable form, such as its oxide, hydroxide, or sulphide.

27. Ion exchange process is also called as
A. permutit’s process
B. demineralization
C. zeolite process
D. lime soda process

Answer: B demineralization
Explanation: ion exchange process is also called as the demineralization. the zeolite process is otherwise called as the ion exchange process.

28. The operational cost of the ion exchange process is
A. high
B. low
C. very high
D. very low

Answer: B low
Explanation: the capital cost of the ion exchange process is very high. the operational cost of the ion exchange process is about low.

29. The hardness in the ion exchange process is reduced to
A. 0-1ppm
B. 0-2ppm
C. 0-3ppm
D. 0-4ppm

Answer: B 0-2ppm
Explanation: the hardness of the ion exchange process is reduced to 0 to 2ppm. it

30. The total are removed completely in the ion exchange process.
A. dissolved gases
B. dissolved solids
C. dissolved solvents
D. dissolved other impurities

Answer: B dissolved solids
Explanation: the total dissolved solids are removed completely in the ion exchange process. in lime soda process, the total dissolved solids are reduced only.

31. In ion exchange process, the iron and manganese ions are removed from the water.
A. true
B. false

Answer: A true
Explanation: in ion exchange process, not only iron and manganese ions are removed from the water but also all the cations are removed.

32. Water softened during method will be ideal in boilers.
A. zeolite method
B. lime soda method
C. demineralisation method
D. permutit’s process

Answer: B lime soda method
Explanation: water softened during the demineralisation method is completely free from all the impurities and flaws. so, the water after the softening by this method will be ideal for boilers.

33. The regeneration of acids and alkalis in ion exchange process is
A. cheaper
B. costlier
C. time taking
D. hard process

Answer: B costlier
Explanation: the one of the disadvantages of the ion exchange process is the regeneration of the acids and alkalis in ion exchange process is costlier.

34. In ion exchange process, the cation exchange resin is generated by passing
A. acids
B. dilute acids
C. alkalis
D. dilute alkalis

Answer: B dilute acids
Explanation: in ion exchange process, the cation exchange resin is generated by passing the dilute acids. the anion exchange resin is generated by passing alkali.

35. In the case of the zeolites, ion exchange process do not function properly because of the
A. turbidity
B. suspended matter
C. turbidity and suspended matter
D. neither turbidity nor suspended matter

Answer: C turbidity and suspended matter
Explanation: in case of zeolites, ion exchange process do not function properly because of the turbidity and suspended matter as they send to cover the surface of the resin.

36. The initial equipment in the ion exchange process is
A. more
B. less
C. very less
D. very high

Answer: A more
Explanation: the initial equipment in the ion exchange process is more. continuous supply of softened water can be made available by providing storage facilities.

37. The residual hardness after the treatment of water is about
A. 1 ppm
B. less than 1ppm
C. 2 ppm
D. less than 2pmm

Answer: D less than 2pmm
Explanation: the residual hardness after the treatment of the water is about less than 2ppm. so, they are suitable for the high pressure boilers.

38. The continuous supply of soft water can be provided by having
A. storage facilities
B. required amount of ppm
C. high pressure boilers
D. 1ppm

Answer: A storage facilities
Explanation: the continuous supply of soft water can be provided by having storage facilities and also two columns of each resin.

39. The cost of the resins used in the ion exchange process is
A. high
B. low
C. moderate
D. depends on water

Answer: A high
Explanation: the cost of the resins used in the ion exchange process is high and the regeneration of the resins in also a costly process.

40. The mineral free water is not used in
A. pharmaceuticals
B. cosmetics
C. explosives
D. drinking

Answer: D drinking
Explanation: in drinking water some minerals must be present. in pharmaceuticals, cosmetics, explosives and in other manufacturing processes, the mineral free water is used.

41. In which process of water softening, ion exchange phenomenon takes place?
A. lime soda process
B. zeolite process
C. boiling
D. demineralization process

Answer: B zeolite process
Explanation: in the zeolite process, calcium and magnesium are removed from hard water by ion exchange phenomenon.

42. In which process of water softening, the chemicals are added to remove hardness from water?
A. lime soda process
B. zeolite process
C. boiling
D. demineralization process

Answer: A lime soda process
Explanation: in the lime soda process, lime and soda are added to remove temporary and permanent hardness from water.

43. Zeolites are complex compound of
A. aluminium and lime
B. silica and soda
C. aluminium, silica and soda
D. lime and soda

Answer: C aluminium, silica and soda
Explanation: zeolites are complex compound of aluminium, silica and soda. it has the property of removing calcium and magnesium from water and substituting sodium in their place.

44. The color of the artificial zeolite permutit is
A. grey
B. yellow
C. green
D. white

Answer: D white
Explanation: the artificial zeolite permutit has a large and lustrous grain. they are white in color and has an appearance of coarse sand.

45. Natural zeolite is mainly processed from
A. white sand
B. green sand
C. grey sand
D. red sand

Answer: B green sand
Explanation: the natural zeolite is mainly processed from green sand, which is also called as glauconite. it has lesser exchange value than artificial zeolite.

46. The color of the natural zeolite is
A. green
B. grey
C. black
D. blue

Answer: A green
Explanation: the color of the natural zeolite is green as it is processed from glauconite which is green in color. it has an exchange value of 6500-9000gm of hardness per m3 of zeolite.

47. The chemical formula of Permutit is
A. sioal2o3na2o
B. sio2al2o3na2o
C. sio2al2o3nao
D. sio3al2o3na2o

Answer: B sio2al2o3na2o
Explanation: the chemical formula of permutit is sio2al2o3na2o. the increase in the value of sio2 increases its resistance to aggressive attacks.

48. The zeolite process is unsuitable for water containing iron and manganese.
A. true
B. false

Answer: A true
Explanation: iron and manganese bearing water deposit hydroxides on the surface of zeolite or react with zeolite to substitute iron and manganese for sodium, which is an irreversible reaction. this makes the zeolite process unsuitable.

49. The thickness of the layers of filter sand of zeolite softener is
A. 20cm
B. 30cm
C. 40cm
D. 100cm

Answer: D 100cm
Explanation: the thickness of the layers of filter sand of zeolite softener lies in the range of 75 to 150cm and their functioning is similar to the rapid sand filter.

50. Salt cannot be separated from brackish water by freezing.
A. true
B. false

Answer: B false
Explanation: salt can be separated from brackish water by freezing.

51. Electrodialysis is based on the fact that the ions present in saline water migrate towards their respective electrodes under the influence of applied
A. current
B. resistance
C. conductance
D. emf

Answer: D emf
Explanation: electrodialysis is based on the fact that the ions present in saline water migrate towards their respective electrodes under the influence of applied emf. the potential difference generated between the elctrodes is the main cause of flow of electrons.

52. The cation selective membrane is embedded with functional groups of
A. positive charge
B. negative charge
C. both positive as well as negative charge
D. neutral

Answer: B negative charge
Explanation: the cation selective membrane is embedded with functional groups of negative charge as it attracts only positive charges towards them.

53. Electrodialysis is an electrically driven separation conducted at a very low pressure- driven, size-exclusion filtering process.
A. true
B. false

Answer: A true
Explanation: electrodialysis is an electrically driven separation conducted at a very low pressure-driven, size-exclusion filtering process. electrodialysis is used to transport salt ions from one solution through ion- exchange membranes to another solution under the influence of an applied electric potential difference.

54. The ion-exchange membrane are electrically conductive and are not permeable to flow, even under pressure.
A. electron
B. oil
C. fluorine
D. water

Answer: D water
Explanation: the ion-exchange membrane are electrically conductive and impermeable to water flow, even under pressure. electrons can easily flow through these membranes.

55. Select the incorrect statement from the following option.
A. electrodialysis reversal (edr) was introduced in the commercial sector to improve electrodialysis process
B. the edr process and conventional ed unit operates on the same principle, except at intervals of several times an hour
C. the reversal feature is useful in breaking up films, scales and other deposits
D. electrodialysis process is not economical as per capital cost

Answer: D electrodialysis process is not economical as per capital cost
Explanation: electrodialysis process is economical as per capital cost and operational expenses are concerned. all the other options are correct.

56. Which one of the following is not a cation exchanger?
A. amberlite
B. triolite
C. dowex
D. duolite

Answer: B triolite
Explanation: triolite is not a cation exchanger. amberlite, dowex and duolite are some of the examples of the cation exchanger.

57. The the salt rejection, the better the system is performing.
A. higher
B. lower
C. moderate
D. poor

Answer: A higher
Explanation: the higher the salt rejection, the better the system is performing. a low salt rejection can mean that the membranes require cleaning or replacement.

58. What is the osmotic pressure for sea water?
A. 1.5 mpa
B. 1.8 mpa
C. 2.3 mpa
D. 2.45 mpa

Answer: D 2.45 mpa
Explanation: the osmotic pressure of sea water is 2.45 mpa. the concentration of salt in sea water is 32000-35000 mg/l. the applied pressure on the ro equipment is 5.6- 6.

59. Membrane permeation rate increases proportionally to effective pressure.
A. true
B. false

Answer: A true
Explanation: although membrane permeation rate increases proportionally to effective pressure, the highest recommended applied pressure of commercial membranes presently available is 7.0 mpa.

60. RO membranes are made of
A. plastic
B. cotton
C. silk
D. polymer

Answer: D polymer
Explanation: the highest recommended applied pressure of commercial membranes presently available is 7.0 mpa; beyond which compaction will start to occur due to the fact that ro membranes are made of polymers.

61. Concentrated seawater which is called
A. permeate
B. brine
C. ro water
D. salt water

Answer: B brine
Explanation: when fresh water is separated from seawater, concentrated seawater which is called brine and is retained on the surface of the ro membrane.

62. 7 REVERSE OSMOSIS.
A. true
B. false

Answer: A true
Explanation: the salt concentration and the osmotic pressure of the brine are related proportionally, i.e., the osmotic pressure of the brine increases as the salt concentration increases.

63. The upper limit of brine concentration is
A. 1.5
B. 2
C. 2.5
D. 3

Answer: C 2.5
Explanation: the upper limit of the brine concentration is usually fixed. the upper limit is normally 1.6-2.5 times that of the normal seawater.

64. What is the maximum acceptable limit of temperature for RO?
A. 20˚c
B. 30˚c
C. 40˚c
D. 50˚c

Answer: C 40˚c
Explanation: in order to reduce the effects of temperature to a minimum, the acceptable

65. What is the design temperature of RO systems?
A. 20˚c
B. 25˚c
C. 30˚c
D. 35˚c

Answer: B 25˚c
Explanation: ro systems are usually designed to operate at 25°c and water flux falls by 20–25 percent when water temperature is lowered by 10°c.

66. What is the thumb rule to consider for osmotic pressure?
A. 1 psi for every 86 ppm of na
B. 2 psi for every 86ppm of na
C. 1 psi for every 43 ppm of na
D. 2 psi for every 43 ppm of na

Answer: A 1 psi for every 86 ppm of na
Explanation: the tendency of a pure solution constituting low solute concentration to flow into solution constituting higher solute concentration is known as osmosis. when pressure greater than osmotic pressure is applied then reverse osmosis takes place. the thumb rule for the consideration of osmotic pressure is 1 psi for every 86 ppm of na.

67. What is the flux considered while designing a reverse osmosis system for treating RO permeate?
A. 30-40 lmh
B. 12-18 lmh
C. 20-25 lmh
D. 25-30 lmh

Answer: A 30-40 lmh
Explanation: flux is the amount of water flowing through a particular area. this is dependent both on the nature of water and the membrane surface area. the flux considered for ro permeate is 30-40 lmh.

68. What is the flux considered while designing a reverse osmosis system for treating bore well water?
A. 30-40 lmh
B. 40-50 lmh
C. 20-30 lmh
D. 12-18 lmh

Answer: C 20-30 lmh
Explanation: the flux increases with increase in pressure. it also increases with increase in temperature. in case of bore well water, the flux considered is 20-30 lmh.

69. What is the flux considered while designing a reverse osmosis system for treating surface water?
A. 15-22 lmh
B. 22-30 lmh
C. 12-15 lmh
D. 30-35 lmh

Answer: A 15-22 lmh
Explanation: the flux to be considered depends on the nature of the water to be treated. the flux is used to determine the number of membranes required for the treatment system. in the case of treating surface water by a conventional method the flux to be considered is 15-22 lmh.

70. What is the flux considered while designing a reverse osmosis system for treating surface water with UF system?
A. 15-20 lmh
B. 20-30 lmh
C. 12-15 lmh
D. 30-35 lmh

Answer: B 20-30 lmh
Explanation: the flux to treat surface water by a conventional method and to treat by uf differs. conventional method includes dual media filters. in case the surface water is treated by conventional, the flux considered should be around 20-30 lmh.

71. What do you mean by the term “Sorption”?
A. attachment
B. detachment
C. diffusion
D. thermal expansion

Answer: A attachment
Explanation: sorption is a physical and chemical process by which one substance becomes attached to another. the reverse of sorption is desorption.

72. The desorption curve is higher than the adsorption curve.
A. true
B. false

Answer: A true
Explanation: theoretically, desorption curve is higher than adsorption curve in low pressure area if the material is mesoporous (2-50nm). if the material is microporous (<2nm), both curves should be matched together.

73. Which of the following isotherm is applicable to physical adsorption?
A. langmuir
B. bet
C. freundlich
D. kisluik

Answer: C freundlich
Explanation: the freundlich isotherm was the first isotherm model proposed for sorption processes. it can be applied for non ideal sorption on heterogeneous surfaces, as well as, multilayer sorption. a variation in the slope between 0 and 1 is associated with a chemisorption process, which is more heterogeneous as the value gets closer to 0.

74. Which type of isotherm is given from the figure, Choose from the following options?
A. type 1 adsorption isotherm
B. type 2 adsorption isotherm
C. type 3 adsorption isotherm
D. type 4 adsorption isotherm

Answer: A type 1 adsorption isotherm
Explanation: the above graph depicts monolayer adsorption. this graph can be easily explained using langmuir adsorption isotherm. examples of type-i adsorption are adsorption of nitrogen (n2) or hydrogen (h) on charcoal at temperature near to -1800c.

75. Which of the following statements regarding the physical adsorption of a gas on surface of solid is not correct?
A. on increasing temperature, adsorption increases continuously
B. enthalpy changes are negative
C. adsorption is specific
D. it is reversible in nature

Answer: A on increasing temperature, adsorption increases continuously
Explanation: physisorption is exothermic in nature. therefore according to le chateliars principle, it occurs readily at low temperature and decreases with increase in temperature.

76. Which of the following is not characteristic of chemisorption?
A. it is irreversible
B. it is specific
C. it is multilayer phenomenon
D. heat of adsorption is about 400kj

Answer: C it is multilayer phenomenon
Explanation: chemisorption involves formation of chemical bonds between adsorbate and adsorbent molecules. once the valency is satisfied, the adsorbent molecules can’t form bond with more adsorbate molecules. thus only one layer is formed.

77. For an adsorbant-adsorbate system obeying the Langmuir adsorption isotherm, b = 0.48 bar-1 and p = 0.16 bar-1. At what pressure will 50% of the surface be covered?
A. 0.05 bar
B. 0.07 bar
C. 0.08 bar
D. 0.04 bar

Answer: B 0.07 bar
Explanation: given data b = 0.48 bar-1

78. Adsorption of methane follows the Langmuir adsorption isotherm at 90K. If p = 1.896cm3g-1bar-1 and b = 0.146bar-1. Calculate the value of θ.
A. 0.116 bar
B. 0.514 bar
C. 0.214 bar
D. 0.216 bar

Answer: D 0.216 bar
Explanation: given data p = 1.896cm3g-1 bar-1

79. In Langmuir’s model of adsorption of a gas on a solid surface the mass of gas striking a given area of surface is to the pressure of the gas.
A. proportional
B. anti proportional
C. independent
D. none of the mentioned

Answer: A proportional
Explanation: in langmuir’s model of adsorption of a gas on a solid surface the mass of gas striking a given area of surface is proportional to the pressure of the gas.

80. The physical process that occurs when gas or liquid molecules are brought into contact with a solid surface and condense on the surface
A. absorption
B. adsorption
C. both adsorption and absorption
D. none of the mentioned

Answer: B adsorption
Explanation: adsorption is the physical process that occurs when gas or liquid molecules are brought into contact with a solid surface and condense on the surface.

81. Adsorption when interaction between the solid and the condensed molecules is relatively strong as contrasted with physical adsorption.
A. absorption
B. adsorption
C. chemisorption
D. none of the mentioned

Answer: B adsorption
Explanation: “chemisorption is the adsorption when interaction between the solid and the condensed molecules is relatively strong as contrasted with physical adsorption.

82. The gas molecules are held on solid surface by in physical adsorption.
A. chemical forces
B. gravitational forces
C. electrostatic forces
D. vander waal’s forces

Answer: D vander waal’s forces
Explanation: chemisorption is the adsorption when interaction between the solid and the condensed molecules is relatively strong as contrasted with physical adsorption.

83. The extent of adsorption of a gas on a solid depend on
A. nature of gas
B. pressure of gas
C. temperature of the system
D. all of the mentioned

Answer: D all of the mentioned
Explanation: the extent of adsorption of a gas on a solid depend on all three nature of gas, pressure of gas and temperature of the system.

84. Which of the following gases is adsorbed by charcoal?
A. nh3
B. h2
C. n2
D. co2

Answer: A nh3
Explanation: nh3 is easily liquefiable and highly water soluble gas.

85. Langmuir isotherm Mathematical relation for that takes place at equilibrium.
A. absorption
B. adsorption
C. both adsorption and absorption
D. none of the mentioned

Answer: B adsorption
Explanation: langmuir isotherm mathematical relation for adsorption that takes place at equilibrium.

86. Adsorption process must be
A. endoethrgic
B. endothermic
C. exothermic
D. none

Answer: C exothermic
Explanation: adsorption process is an exothermic process.

87. The rate law for a reaction between the substances A and B is given by rate = K[A]n [B]m. On doubling the concentration of A and halving the concentration of B. What will be the ratio of the new rate of the earlier rate of the reaction?
A. ( 1 )m+n
B. m2+n
C. n-m
D. 2n-m

Answer: D 2n-m

88. On which factor the rate constant of a reaction does not depend upon?
A. temperature
B. activation energy
C. catalyst
D. concentration of reactants and products

Answer: D concentration of reactants and products
Explanation: the rate constant of reaction does not depend on concentration of reactant & product (only on nature of reactant & product).

89. The rate of reaction, A + B Products, is given by the equation, r = k[A][B]. If B is taken in excess, what would be the order of reaction?
A. 2
B. 1
C. zero
D. unpredictable

Answer: B 1
Explanation: a + b → products

90. In a reaction, 2A2 + B2 → 2A2B, when the reactant A will disappear?
A. half the rate that b will decrease
B. the same rate that b will decrease
C. double the rate that a2b will form
D. twice the rate that b will decrease

Answer: D twice the rate that b will decrease

91. The rate of reaction that does not involve gases, is not dependent on
A. pressure
B. temperature
C. concentration
D. catalyst

Answer: A pressure
Explanation: the rate of reaction that does not involve gases does not depend on pressure.

92. Which is not true for a second order reduction?
A. it can have rate constant 1 x 10-2 l mol-1 s- 1
B. its half-life is inversely proportional to its initial concentration
C. time to complete 75% reaction is twice of half-life
D. t50 = 1/(ka⋅a0)

Answer: C time to complete 75% reaction is twice of half-life

93. The rate of decomposition of a substance increases concentration of substance at same temperature. Find out order of reaction.
A. 1
B. 2
C. 3
D. 0

Answer: B 2
Explanation: rate = k [a]α r1 = k[a]n

94. Molecularity of a reaction is equal to the total number of
A. products formed in the elementary step
B. reactants taking part in elementary step
C. reactants and products in the elementary step
D. reactants and products in the final step

Answer: B reactants taking part in elementary step
Explanation: molecularity of a reaction is equal to the total number of reactants taking part in an elementary step. it is defined as the number of molecules or ions that participate in the rate determining step.

95. Which of the following statement is incorrect about the molecularity of a reaction?
A. it is a theoretical concept
B. each step of a multi-step reaction has a unique molecularity
C. it is equal to the total number of reactants taking part in elementary step
D. it can be zero, fractional or integer

Answer: D it can be zero, fractional or integer
Explanation: molecularity is always a whole number. it can be neither zero nor fractional. all the other options are correct.

96. Which of the following factor does not effect the rate of reaction?
A. concentration of the reactant
B. temperature
C. pressure
D. effect of catalyst

Answer: C pressure
Explanation: the reaction rate does not depend upon the pressure. it only depends upon the concentration of the reactant, temperature and effect of catalyst.

97. The reaction rate is greatly influenced by
A. nature of bond in the reactant molecules
B. strength of bond in the reactant molecules
C. both nature and strength of the reactant molecules
D. it does not depend on either nature or strength of the reactant molecules

Answer: C both nature and strength of the reactant molecules
Explanation: the reaction rate is greatly influenced by both nature and strength of the reactant molecules. reactants are the major factor that affects the rate of the reaction.

98. The reactions register an increase in rates in the presence of radiations of specific wavelengths.
A. true
B. false

Answer: A true
Explanation: the reactions register an increase in rates in the presence of radiations of specific wavelengths.

99. Select the correct option from the following option.
A. catalyst is used to increase the rate of reaction by altering chemically during the course of reaction
B. catalyst is used to decrease the rate of reaction by altering chemically during the course of reaction
C. catalyst is used to increase the rate of reaction and remains unaltered chemically during the course of reaction
D. catalyst is used to decrease the rate of reaction and remains altered chemically during the course of reaction

Answer: C catalyst is used to increase the rate of reaction and remains unaltered chemically during the course of reaction
Explanation: catalyst is used to increase the rate of reaction and remains unaltered chemically during the course of the reaction. with a catalyst, reactions occur faster and require less activation energy. because catalysts are not consumed in the catalyzed reaction, they can continue to catalyze the reaction of further quantities of reactant.

100. Which of the following is not an adsorbent?
A. carbon
B. polymers and resins
C. clay
D. dry sponge

Answer: D dry sponge
Explanation: a sponge will absorb or take in water from another area and put it inside of itself. a dry sponge can hold more water than a wet sponge is closer to saturation and as such cannot hold more water. sponges with more tiny holes can absorb more water than the sponges with less tiny holes and thus leads to the absorption process.

101. Which of the following is not a characteristic of a catalyst?
A. it participates in the reaction
B. it enhances the equilibrium rate
C. it activates equilibrium
D. it initialises the reaction

Answer: A it participates in the reaction
Explanation: the main purpose of using a catalyst is only to increase the rate of achieving the equilibrium state in case of slow reaction. other than that it will not initiate or involve in the reaction.

102. Which of the following will decrease the rate of reaction?
A. catalytic poison
B. positive catalyst
C. negative catalyst
D. catalytic promoters

Answer: A catalytic poison
Explanation: catalytic poisons are the once which are used to slow down the reaction inorder to avoid explosion when the temperature or pressure increase the critical value. hence catalytic poisons are used such as aluminium oxide.

103. Which of the following is a catalytic poison?
A. potassium nitrate
B. aluminium nitrate
C. aluminium oxide
D. chlorine

Answer: C aluminium oxide
Explanation: aluminium oxide is known for its sophisticated properties and is mainly used in the process of corrosion preventing it absorbs moisture and has high retentivity and hence is used as a catalytic poison.

104. Which of the following is used as a catalytic promoter?
A. chlorine
B. nitrate
C. bromine
D. helium

Answer: B nitrate
Explanation: the use of a promoter is to increase the rate of equilibrium. we know that nitrogen has promoting properties in the case of nitrate molecules. thus the can act as good promoters in reaction.

105. Where is the intermediate theory used?
A. heterogeneous components
B. homogeneous components
C. miscible components
D. immiscible components

Answer: A heterogeneous components
Explanation: intermediate theory is the process in which an intermediate product is formed and hence it is suitable for homogeneous components and not for heterogeneous components.

106. Lambda PL promoter is used in which vectors?
A. cloning vectors
B. expression vectors
C. both cloning and expression vectors
D. bacteriophage mu

Answer: B expression vectors
Explanation: lambda pl promoters are the promoters for the left region in bacteriophage lambda. it is widely used in expression vectors.

107. The promoter can be controlled by a repressor which is temperature sensitive.
A. true
B. false

Answer: A true
Explanation: the promoter is activated at a temperature higher than 30 degrees because at this temperature repressor is inactivated.

108. The operon encodes proteins involved in arabinose metabolism.
A. arabcd
B. araabd
C. arabad
D. aradba

Answer: C arabad
Explanation: the arabad operon encodes proteins involved in arabinose metabolism. it is controlled by arac transcriptional regulator.

109. tac promoter is an example of which type of promoter?
A. hybrid promoter
B. fusion promoter
C. lacz promoter
D. arabad promoter

Answer: A hybrid promoter
Explanation: hybrid promoters are those promoters which are produced by two promoters from different sources. tac promoter is a hybrid promoter produced from trp promoter and lacuv5 promoter.

110. The tac promoter is made by region of trp promoter and region of the lacUV5 promoter.
A. 10, 35
B. 35, 10
C. 10, 10
D. 35, 35

Answer: B 35, 10
Explanation: it is a hybrid promoter made by 35 regions of trp promoter and 10 regions of the lacuv5 promoter.

111. The tac promoter includes the lac operator and is regulated by a repressor.
A. true
B. false

Answer: A true
Explanation: the tac promoter includes the lac operator and is regulated by the repressor. the repressor is to be supplied by the host.

112. Expression of T7 promoter- lac operator hybrid requires
A. t7 rna polymerase
B. an inducer such as iptg
C. both t7 rna polymerase and inducer such as iptg
D. t7 dna polymerase

Answer: C both t7 rna polymerase and inducer such as iptg
Explanation: expression of t7 promoter- lac operator hybrid requires both t7 rna polymerase and inducer such as iptg. if inducer is absent levels of expression are very low.

113. When lacUV5 control system is used, addition of IPTG the expression of
A. activates, t7 rna polymerase
B. inactivates, t7 rna polymerase
C. activates, t7 dna polymerase
D. inactivates, t7 dna polymerase

Answer: A activates, t7 rna polymerase
Explanation: when a lacuv5 control system is used, the addition of iptg activates the expression of t7 rna polymerase. thus transcription of sequences under the control of t7 promoter is controlled.

114. A is a biocatalyst that increases the rate of the reaction without being changed.
A. aluminum oxide
B. silicon dioxide
C. enzyme
D. hydrogen peroxide

Answer: C enzyme
Explanation: among these options, an enzyme is an only option which is a biocatalyst that catalyzes the chemical reaction without being changed while all other options are of the catalyst which increases or decrease the rate of reaction based on their concentration.

115. Enzyme increases the rate of reaction by lowering the activation energy.
A. true
B. false

Answer: A true
Explanation: activation energy is the difference in free energy between the reactants and transition state. to complete a reaction, enzyme lowers the activation energy and crosses the transition state.

116. What is the nature of an enzyme?
A. vitamin
B. lipid
C. carbohydrate
D. protein

Answer: D protein
Explanation: all enzymes are protein except catalytic rna molecule. the native protein conformation of an enzyme defines its catalytic activity. once the enzyme is denatured, its catalytic activity is also lost.

117. What is an apoenzyme?
A. it is a protein portion of an enzyme
B. it is a non-protein group
C. it is a complete, biologically active conjugated enzyme
D. it is a prosthetic group

Answer: A it is a protein portion of an enzyme
Explanation: removal of cofactor from a conjugated enzymes forms apoenzyme which is a protein component. a cofactor is a non- protein group while a complete conjugated enzyme is known as a holoenzyme.

118. Name the coenzyme of riboflavin (B2)?
A. nad or nadp
B. fad and fmn
C. coenzyme a
D. thiamine pyrophosphate

Answer: B fad and fmn
Explanation: riboflavin is a part of vitamin b complex, its coenzyme form is a fad (flavin adenine dinucleotide) which involves a redox reaction. nad is a coenzyme form of nicotinic acid, and thiamine pyrophosphate is a coenzyme of thiamine.

119. Which of this vitamin is associated with the coenzyme Biocytin?
A. nicotinic acid
B. thiamine
C. biotin
D. pyridoxine

Answer: C biotin
Explanation: biocytin is a coenzyme of biotin which involves in carboxylation reaction while thiamine takes part in decarboxylation reaction.

120. Name the enzyme secreted by pancreas?
A. pepsin
B. chymotrypsin
C. trypsin
D. alcohol dehydrogenase

Answer: C trypsin
Explanation: trypsin is a proteolytic enzyme, secreted by the pancreas. it is one of the three digestive proteinases along with pepsin and chymotrypsin which breaks down dietary protein molecules into simpler forms.

121. Name the enzyme which catalyzes the oxidation-reduction reaction?
A. transaminase
B. glutamine synthetase
C. phosphofructokinase
D. oxidoreductase

Answer: D oxidoreductase
Explanation: oxidoreductase is a class of enzyme which catalyze the oxidation- reduction reaction. some of the oxidoreductase enzymes are oxidases, dehydrogenases, peroxidases etc.

122. What is the function of phosphorylase?
A. transfer inorganic phosphate
B. transfer a carboxylate group
C. use h2o2 as the electron acceptor
D. transfer amino group

Answer: A transfer inorganic phosphate
Explanation: phosphorylase is a transferase enzyme which involves a transfer of inorganic phosphate to a substrate while transcarboxylase transfer a carboxylate group and transaminase transfer amino group from amino acid to the keto acid.

123. Mark the CORRECT function of enzyme, Peptidase?
A. cleave phosphodiester bond
B. cleave amino bonds
C. remove phosphate from a substrate
D. removal of h2o

Answer: B cleave amino bonds
Explanation: hydrolases are the enzymes which cleave the bond by adding water.

124. Which of the following reaction is catalyzed by Lyase?
A. breaking of bonds
B. formation of bonds
C. intramolecular rearrangement of bonds
D. transfer of group from one molecule to another

Answer: A breaking of bonds
Explanation: lyase is the class of enzymes which does not involve hydrolysis or oxidation to break the bond. it catalyzes the breaking of c-c, c-o, c-n, c-s bonds by the process of elimination and results in the formation of a double bond.

125. Which of the following is true about Michaelis-Menten kinetics?
A. km, the michaelis constant, is defined as that concentration of substrate at which enzyme is working at maximum velocity
B. it describes single substrate enzymes
C. km, the michaelis constant is defined as the dissociation constant of the enzyme- substrate complex
D. it assumes covalent binding occurs between enzyme and substrate

Answer: B it describes single substrate enzymes
Explanation: km is defined as the concentration of substrate at which enzyme is working at half of maximum velocity. it is also a measure of the affinity that the enzyme has for its substrate. michaelis-menten kinetics assumes non-covalent binding between enzyme and substrate.

126. When the velocity of enzyme activity is plotted against substrate concentration, which of the following is obtained?
A. hyperbolic curve
B. parabola
C. straight line with positive slope
D. straight line with negative slope

Answer: A hyperbolic curve
Explanation: at low substrate concentration, the rate of a reaction is determined by the rate of formation of an enzyme-substrate complex.

127. Which of the following is an example for irreversible inhibitor?
A. disulfiram
B. oseltamivir
C. protease inhibitors
D. dipf

Answer: D dipf
Explanation: disulfiram, oseltamivir and protease inhibitors are reversible inhibitors.

128. Where does inhibitor binds on enzyme in mixed inhibition?
A. at active site
B. allosteric site
C. does not bind on enzyme
D. binds on substrate

Answer: B allosteric site
Explanation: the inhibitor binds at a place different from active site allosterically.

129. The catalytic efficiency of two distinct enzymes can be compared based on which of the following factor?
A. km
B. product formation
C. size of the enzymes
D. ph of optimum value

Answer: A km
Explanation: km is the substrate concentration. increased substrate concentration increases the rate of reaction.

130. What is the general mechanism of an enzyme?
A. it acts by reducing the activation energy
B. it acts by increasing the activation energy
C. it acts by decreasing the ph
D. it acts by increasing the ph

Answer: A it acts by reducing the activation energy
Explanation: for the reaction to occur at a faster rate, activation energy should be less.

131. What kind of steel requires definite amounts of other alloying elements?
A. carbon steel
B. alloying steel
C. stainless steel
D. tool steel

Answer: B alloying steel
Explanation: alloy steels are those steels which require a specific amount of the elements making up its composition. alloy steels consist of manganese, silicon, and copper as primary elements whose quantities are equal to or more than 1.65%, 0.60%, and 0.60% respectively.

132. Which of these is not a function of alloy steels?
A. increases strength
B. improves ductility
C. reduces cost
D. improves machinability

Answer: C reduces cost
Explanation: alloy steels are used to improve properties such as strength, hardness, ductility, grain structure, and machinability, among others. this, however, results in increased costs due to multiple elements involved in the process.

133. 1 ALLOYS: INTRODUCTION- DEFINITION- PROPERTIES OF ALLOYS- SIGNIFICANCE OF ALLOYING, FUNCTIONS AND EFFECT OF ALLOYING ELEMENTS
A. low alloy steels
B. hsla steels
C. high alloy steels
D. stainless steels

Answer: A low alloy steels
Explanation: low alloy steels consist of 3% to 4% of alloying elements making up its composition. they have similar microstructure and heat treatments as plain carbon steels. hsla and aisi steels are the types of low alloy steels.

134. What does AISI steel stand for?
A. american-indian steel institute
B. american-indian society of iron
C. american iron and steel institute
D. alloys, iron and steel institute

Answer: C american iron and steel institute
Explanation: american iron and steel institute (aisi) is an association, established in america, which produces steel. aisi steels are used in machine construction. they are otherwise known as construction steels or structural steels.

135. Which of these is not an application of HSLA steels?
A. bridges
B. automobiles and trains
C. building columns
D. leaf and coil springs

Answer: D leaf and coil springs
Explanation: hsla steels are known as high-strength-low-alloy steels. these high strength steels are primarily used as structural materials or construction alloys. they are used to reduce weight on bridges, automobiles, pressure vessels, building columns, etc.

136. Steels containing more than 5% of one or more alloying elements are known as
A. hsla steels
B. high alloy steels
C. tool and die steels
D. stainless steels

Answer: B high alloy steels
Explanation: high alloy steels are composed of more than 5% of alloying elements. they have different microstructure and heat treatments than those of plain carbon steels. tool and die, and stainless steels are the types of high alloy steels.

137. Which of the following groups of alloying elements stabilize austenite?
A. ni, mn, cu, and co
B. cr, w, mo, v, and si
C. cr, w, ti, mo, nb, v, and mn
D. co, al, and ni

Answer: A ni, mn, cu, and co
Explanation: the alloying elements such as ni, mn, cu, and co have a tendency to alleviate austenite, whereas cr, w, mo, v, and si tend to stabilize ferrites. alloying elements such as cr, w, ti, mo, nb, v, and mn tend to form carbides. other elements like co, al, and ni help to weaken carbides and thereby form graphite.

138. Which family of steels are referred to as chromoly?
A. 40xx
B. 41xx
C. 43xx
D. 44xx

Answer: B 41xx
Explanation: the family of 41xx steel is usually called as chromoly or chrome-moly due to its primary alloying elements, chromium and molybdenum. steels such as 4130 and 4140 are generally used for bicycle frames, and as parts of firearms, flywheels etc.

139. What is the common name of COR-TEN steel?
A. weathering steel
B. control-rolled steel
C. pearlite-reduced steel
D. microalloyed steel

Answer: A weathering steel
Explanation: weathering steels are otherwise also known as cor-ten or corten steels.

140. Alloy steels containing 0.05% to 0.15% of alloying elements are called
A. weathering steel
B. stainless steel
C. tool and die steel
D. microalloyed steel

Answer: D microalloyed steel
Explanation: microalloyed steels contain alloying elements in small quantities (0.05% to 0.15%). these elements include niobium, vanadium, titanium, molybdenum, rare earth metals, among others. they are used to refine the microstructure of the grain or for precipitate hardening process.

141. Which is the primary element used for making stainless steel alloy?
A. chromium
B. zirconium
C. vanadium
D. indium

Answer: A chromium
Explanation: stainless steels contain iron and a minimum of 10.5% of chromium. this gives it great resistance to corrosion.

142. Addition of gives stainless steels an austenitic structure.
A. molybdenum
B. carbon
C. nickel
D. vanadium

Answer: C nickel
Explanation: nickel is added to stainless steels with a 3.5% to 22% composition to form austenitic structure. this results in the highest corrosion resistance among all stainless steels. they also possess high strength and ductility.

143. Stainless steels with little carbon and no nickel are called
A. ferritic stainless steel
B. austenitic stainless steel
C. martensitic stainless steel
D. duplex stainless steel

Answer: A ferritic stainless steel
Explanation: ferritic stainless steels are steels containing 12.5% to 17% of chromium. they are nickel¬-free and contain very little carbon making up its composition. they are, therefore, better resistant to corrosion than martensitic stainless steels.

144. Stainless steels with high strength, but low corrosion resistance are known as
A. austenitic stainless steel
B. ferritic stainless steel
C. martensitic stainless steel
D. duplex stainless steel

Answer: C martensitic stainless steel
Explanation: martensitic stainless steels are made of 12-14% chromium, along with molybdenum, nickel, and carbon. this makes the steels hard and brittle, but poorly resistant to corrosion. martensitic stainless steels are used in making swiss army knives.

145. Which of the following is not a type of oil- hardening steel?
A. o1
B. o2
C. o6
D. o9

Answer: D o9
Explanation: oil hardening steels are a group of cold working tool steels. this group consists of o1 (0.9% c, 1% mn, 0.5% cr),

146. Mushet steel belongs to which group of tool steels?
A. oil-hardening steels
B. air-hardening steels
C. high-speed steels
D. hot-working steels

Answer: B air-hardening steels
Explanation: mushet steel was the first air- hardening tool steel. it belongs to the cold- working family of tool steels. it was developed by robert mushet.

147. What property does the AISI-SAE tool steel grade ‘L’ possess?
A. cold-working
B. hot-working
C. plastic mild
D. special purpose

Answer: D special purpose
Explanation: the steel grade ‘l’ refers to special purpose steel containing low alloy. it consists of elements such as carbon, chromium, manganese, and a few others. the l2 and l6 are the most commonly used steels under this category.

148. The low-carbon, high-alloyed steels which possess high strength and toughness are known as
A. carbon steels
B. alloy steels
C. maraging steels
D. stainless steels

Answer: C maraging steels
Explanation: maraging steels are those high strength steels which have tensile strengths up to 1900 mpa. they are composed of 18% ni, 7% co, and less than 0.05% c.

149. What do TRIP steels stand for?
A. transformation induced porosity
B. transformation induced plasticity
C. transformation induced pearlite
D. transformation induced property

Answer: B transformation induced plasticity
Explanation: trip steels are those steels containing high strength and ductility. they are mainly used for automotive industry needs. the expanded form of trip is transformation induced plasticity. it contains an austenite microstructure.

150. What is the maximum allowable temperature at which High-Speed Steels retain good cutting ability?
A. 100oc
B. 200oc
C. 350oc
D. 540oc

Answer: D 540oc
Explanation: high-speed steels have the ability to remove and cut metal at a much

151. Ultra high-speed steels are made of which of the following elements?
A. tungsten and molybdenum
B. chromium and molybdenum
C. vanadium and cobalt
D. molybdenum and cobalt

Answer: C vanadium and cobalt
Explanation: ultra high-speed steels have greater tool lives and greater cutting efficiency. this is due to the addition of vanadium (up to 4%) and cobalt (5% to 12%) along with carbon, chromium, and tungsten.

152. What is the microstructure of Hadfield’s steel?
A. austenite
B. ferrite
C. martensite
D. cementite

Answer: A austenite
Explanation: hadfield’s manganese steels (mangalloy) possess great strength and toughness. its austenite structure is obtained by heating it. this also results in high wear resistance, which finds its applications in bulldozers, crushers, etc.

153. Which of the following is the hardest constituent of steel?
A. ledeburite
B. austenite
C. bainite
D. martensite

Answer: D martensite
Explanation: martensite is the hardest constituent of steel. the primary reasons

154. Iron possesses BCC crystal structure up to (in degree centigrade)?
A. 1539
B. 768
C. 910
D. 1410

Answer: B 768
Explanation: pure iron possess either bcc or fcc crystal structure as its temperature is increased from room temperature to its melting point. at room temperature to 910oc, it is having bcc, between 910oc and 1410oc it is having face centered cubic, and from 1410oc to its melting point (1539oc) it returns to its bcc crystal structure.

155. Iron possesses BCC crystal structure above (in degree centigrade)?
A. 1539
B. 768
C. 910
D. 1410

Answer: D 1410
Explanation: from 1410oc to its melting point (1539oc) iron is having bcc crystal structure.

156. Which of the following form of iron is magnetic in nature?
A. α
B. δ
C. γ
D. λ

Answer: A α
Explanation: the alpha form of iron is magnetic and stable at all temperatures below 910oc.

157. For steel, which one of the following properties can be enhanced upon annealing?
A. hardness
B. toughness
C. ductility
D. resilience

Answer: C ductility
Explanation: a furnace cooling technique, annealing will enhance the ductility of steel, due to the formation of coarse pearlite.

158. In Annealing, cooling is done in which of the following medium?
A. air
B. water
C. oil
D. furnace

Answer: D furnace
Explanation: in annealing, after solutionising, material is used to furnace cool, means furnace is switched off and the steel sample inside is let cool down.

159. In normalizing, cooling is done in which of the following medium?
A. air
B. water
C. oil
D. furnace

Answer: A air
Explanation: in normalizing, steel is heat treated above its critical temperature, solutionised, and then allowed to cool for a long time by keeping it in air. in steel, it forms fine pearlite, which imparts strength to steel.

160. Mild steel can be converted into high carbons steel by which of the following heat treatment process?
A. annealing
B. normalizing
C. case hardening
D. nitriding

Answer: C case hardening
Explanation: case hardening, also referred as carburizing increases carbon content of steel, thus, imparting hardness to steel.

161. Upon annealing, eutectoid steel converts to which of the following?
A. perlite
B. cementite
C. austenite
D. martensite

Answer: A perlite
Explanation: eutectoid steels upon annealing produces pearlite (coarse pearlite). pearlite is an alternate lamellae of ferrite and cementite.

162. What is Gibbs phase rule for metallurgical system?
A. f = c – 1 – p
B. f = c + 1 – p
C. p + f = c – 2
D. p + f = c + 2

Answer: B f = c + 1 – p
Explanation: for metallurgical system pressure has no appreciable effect on phase equilibrium and hence, f = c – p + 1.

163. In a single – component condensed system, if degree of freedom is zero, maximum number of phases that can co – exist
A. 2
B. 3
C. 0
D. 1

Answer: A 2
Explanation: given f = 0 then p = c + 1, c = 1

164. What is degree of freedom when two phases co – exist?
A. 2
B. 3
C. 0
D. 1

Answer: D 1
Explanation: f = c + 1 – p f = 3 – p (c = 2)

165. What is degree of freedom when three phases co – exist?
A. 2
B. 3
C. 0
D. 1

Answer: C 0
Explanation: f = c + 1 – p f = 3 – p (c = 2)

166. When α, L and β phase fields touch the isotherm line what are the respective phase compositions?
A. 8.0 wt%, 71.9 wt%, 91.2 wt% of ag
B. 8.0 wt%, 91.2 wt%, 71.9 wt% of ag
C. 71.9 wt%, 91.2 wt%, 8.0 wt% of ag
D. 91.2 wt%, 8.0 wt%, 71.9 wt% of ag

Answer: A 8.0 wt%, 71.9 wt%, 91.2 wt% of ag
Explanation: for binary systems, when three phases are present, there will be f = 0, so composition is fixed.

167. For binary alloy consisting of three phases of non – equilibrium one, What will be the temperature of these phases?
A. different
B. constant
C. same
D. two of them will be with one temperature

Answer: C same
Explanation: one use of the gibbs phase rule is in analyzing for non – equilibrium conditions by analyzing with above method we come to know (under these circumstances, three phases will exist only at a single temperature).

168. What does Gibb’s phase rule state?
A. p+f=c-1
B. p+f=c+1
C. p+f=c-2
D. p+f=c+2

Answer: D p+f=c+2
Explanation: the above phase rule is a formula that gives the condition for finding the number of phases in a system. this phase rule can be applied to both condensed as well as normal systems.

169. What is the point at which all the three phases of a system exist?
A. triple point
B. sublimation point
C. vapor point
D. eutectic point

Answer: A triple point
Explanation: since at the triple point, the degree of freedom is zero (that is invariant reaction takes place at that point), therefore according to phase rule, f=c-p+2.

170. Liquid phase exists for all compositions above region.
A. eutectic region
B. equilibrium region
C. isometric region
D. sublimation region

Answer: C isometric region
Explanation: in a phase region above the eutectic point, both the solid and liquid phases exist together where the region is bi variant and this region is called isometric region. here the region has 2 degrees of freedom.

171. Select the wrong statements from the following statements with respect to a phase diagram.
A. gives information about concentration
B. gives information about solubility
C. gives information on melting and boiling points
D. gives information on relative concentration

Answer: D gives information on relative concentration
Explanation: a phase diagram gives information only on the concentration of species, their solubility rate, degree of freedom and other physical properties. it does not explain about transformation rates and relative concentration (relative concentration=total concentration/equilibrium concentration).

172. Select a non-homogeneous system from the following.
A. salt solution
B. sugar solution
C. glucose in water
D. saturated solution of nacl

Answer: D saturated solution of nacl
Explanation: a homogeneous mixture is one which is miscible completely with one another. in any saturated solution, when the amount of solute reaches more than a critical point, then the solution becomes heterogeneous.

173. Select the odd statement with respect to a phase reaction.
A. saturated solution
B. equilibrium solution
C. concentric solution
D. amorphous solution

Answer: A saturated solution
Explanation: a terminal solution, an intermediate solution, an equilibrium solution and concentric solutions, are the ones which take part in a phase reaction. on the other hand, a saturated solution is involved in the lever system.

174. Which of the following is the formula for condense phase rule?
A. f=c-p+2
B. f=c-p+1
C. f=c+p-2
D. f=c+p-1

Answer: B f=c-p+1
Explanation: in a condensed phase rule system, the phases are represented in three dimension which is not suitable for graphic purposes and hence the pressure is considered to be zero (this is helpful in drawing 2d images). hence the formula reduces to f=c- p+2.

175. Under what condition, will we get a stable phase diagram?
A. solid + liquid
B. solid + vapor
C. liquid + vapor
D. liquid + solid

Answer: A solid + liquid
Explanation: according to equilibrium mixture ration, an appropriate ratio of 1:10 parts of solid and liquid along with an aqueous solution will give a stable phase product.

176. Thermal analysis is defined as
A. measurement of concentration of materials as a function of temperature
B. measurement of solubility of materials as a function of temperature
C. measurement of physical properties as a function of temperature
D. measurement of line positions of crystals as a function of temperature

Answer: C measurement of physical properties as a function of temperature
Explanation: thermal analysis is defined as the measurement of physical and chemical properties of materials as a function of temperature. in practice, however the term thermal analysis is used to cover certain specific properties only. these are enthalpy, heat capacity, mass and coefficient thermal expansion.

177. What are the two main techniques for thermal analysis?
A. ftg and dgg
B. msp and fct
C. tga and dta
D. tsa and dgf

Answer: C tga and dta
Explanation: the two main thermal analysis techniques are thermogravimetric analysis known as tga which measures the change in weight with temperature and differential thermal analysis known as dta which detects changes in heat content.

178. Dilatometry is also known as by which of the following names?
A. tga
B. dta
C. dsc
D. tma

Answer: D tma
Explanation: a fourth thermal analysis technique is dilatometry in which the change in linear dimension of a sample as a function of temperature is recorded. recently it has acquired a new name, thermomechanical analysis (tma).

179. In thermogravimetric analysis, the result obtained appear as a
A. continuous chart
B. continuous parabola
C. continuous circular positions
D. discontinuous chart

Answer: A continuous chart
Explanation: thermogravimetric is a technique for measuring the change in weight of a substance as a function of temperature or time, the result usually appears a continuous chart record, a schematic, typical, single step decomposition reaction.

180. Under conditions of heating, decomposition usually take place in thermogravimetry. Fill up the suitable option from the choices given below.
A. first order
B. second order
C. third order
D. dynamic

Answer: D dynamic
Explanation: in thermogravimetric analysis (tga), decomposition usually take place under dynamic heating conditions over a range of temperature ti to tf and a second constant weight plateau is then observed above tf, which corresponds to the weight of the residue wf.

181. The Ti and Tf temperature depends on which of the following factor?
A. cooling rate
B. mechanical property of the material
C. thermal expansion coefficient
D. atmosphere above the sample

Answer: D atmosphere above the sample
Explanation: initial and final temperature ti, tf depends on variables such as heating rate, the nature of the solid (e.g. its particle size) and the atmosphere above the sample. the effect of the atmosphere can be dramatic.

182. What is the definition of a lower critical temperature?
A. the minimum temperature at which equilibrium is achieved
B. the lowest temperature at which two components will attain vapor state
C. the lowest temperature at which two components sublimates
D. the lowest temperature at which two components form a mixture

Answer: A the minimum temperature at which equilibrium is achieved
Explanation: the lower critical solution temperature is the lowest temperature at which two components are insoluble and attains equilibrium. conversely, the upper critical solution temperature is the highest temperature at which two components are soluble as single phase.

183. With reference to a two component system, a vapor line indicates
A. a region where the temperature and pressure remains stable
B. a region where the solubility remains constant
C. an area below which components do not mingle
D. an area above which both the components mingle to form a single mixture

Answer: A a region where the temperature and pressure remains stable
Explanation: a vapor line is another name for an isotherm. it represents constant temperature and constant pressure relation at which the equilibrium is obtained. a vapor line helps in finding out equilibrium concentrations.

184. With reference to a two component system, an isobar indicates
A. a region where the temperature remains constant
B. an area below phase end products remains
C. an area above which only the liquid vapors remains
D. a region where the composition lies in equilibrium

Answer: D a region where the composition lies in equilibrium
Explanation: an isobar is a line that indicates a region where the composition remains constant and in the equilibrium state. in a two component solid-liquid system, it is drawn vertically covering a wide range of temperatures.

185. Which of the following statements is not true for a system that has reached the eutectic temperature?
A. the system is a open system
B. the system is a miscible fluid
C. components lie in liquid state
D. a region between sublimation and eutectic curve lies stable

Answer: A the system is a open system
Explanation: the eutectic temperature is achieved by heating a liquid in the point where the density of the liquid state is equal to the density of the vapor state. here, the interface between the liquid and vapor vanishes resulting in a miscible fluid. this can only occur in a closed system (otherwise the vapor would escape into the surroundings).

186. Which of the following statements are correct about the equilibrium point on a two component system?
A. all the compounds are liquid
B. the boiling point of the mixture is less than the boiling points of the individual compounds
C. the degree of freedom is 0
D. invariant reaction takes place

Answer: B the boiling point of the mixture is less than the boiling points of the individual compounds
Explanation: the eutectic point on a phase diagram is a point at which the mixture boils at a temperature lower than that of the pure substances. the substance attains equilibrium state.

187. During metastable state, the size of the particle
A. increases
B. decreases
C. won’t change
D. not related

Answer: A increases
Explanation: since for a system to be in equilibrium condition, its size automatically increases by mond’s effect which is why the particle’s size increases during metastable state due to changes in molecular size.

188. Which of the following is not responsible for phase deposition?
A. container wall
B. grain size
C. stacking effect
D. disjoints

Answer: A container wall
Explanation: under equilibrium conditions, the molecules adhere to the center of the

189. Where does the particle growth occur?
A. movement of grains
B. movement of equilibrium liquid
C. equilibrium mixture
D. non equilibrium mixture

Answer: A movement of grains
Explanation: during diffusion process in the transformation of solid to vapor state, the molecules move from regions of higher concentration to regions of lower concentrations and hence growth takes place n a controlled way.

190. Overall transformation rate changes with temperature as follows under what condition?
A. decreases
B. increases then decreases
C. follows a linear path
D. increases with temperature

Answer: B increases then decreases
Explanation: according to the phase graph, at the solidus region, the temperature is high. as the melting point increases, the temperature decreases and vice versa (applicable to all component systems).

191. Acetylene and synthesis gas are examples of
A. primary gaseous fuels
B. gaseous fuels
C. secondary gaseous fuels
D. liquid fuels

Answer: C secondary gaseous fuels
Explanation: since both acetylene and synthesis gas are formed by certain process and both are gaseous in nature, therefore they are secondary gaseous fuels. acetylene can be formed by the hydrolysis of calcium carbide.

192. Alcohol is a primary fuel.
A. true
B. false

Answer: B false
Explanation: alcohol are formed by direct hydration of alkenes, that is why this is a false statement. formation of ethanol by the hydration of ethylene.

193. Which of the fuel does have highest specific energy?
A. diesel
B. coal
C. kerosene
D. nitromethane

Answer: A diesel
Explanation: specific energy is the amount of energy liberated after combustion, as among these diesel liberated the highest amount of energy which is 48 mj/kg.

194. Which type of coal give more amount of heat after combustion?
A. anthracite
B. peat
C. lignite
D. bituminous

Answer: A anthracite
Explanation: the coal is formed along this process

195. Which fuel is best suitable for blast furnace process?
A. diesel
B. hydrogen gas
C. coal
D. coke

Answer: D coke
Explanation: coke is best suitable for blast furnace process as it also acts as a reducing agent in smelting iron ore. the specific heat of coke is 0.85 kj/kg k.

196. Which fuel causes least pollution?
A. diesel
B. coal
C. lpg (liquid petroleum gas)
D. hydrogen gas

Answer: D hydrogen gas
Explanation: pollution is mainly caused by the presence of co2 in air. since after combustion of h2 it only gives water vapour which is less polluting.

197. Which of the gas is not a constituent of biogas?
A. methane
B. hydrogen
C. co2
D. so2 (sulphur di-oxide)

Answer: D so2 (sulphur di-oxide)
Explanation: since biogas is formed by the domestic waste of home and industries, it does not contain the gases like so2, no2 etc. it does contain the hydrogen sulphide.

198. Which fuel can be produced from the carbohydrate content of algae?
A. butanol
B. hydrogen gas
C. coal
D. lpg (liquid petroleum gas)

Answer: A butanol
Explanation: the carbohydrate part of algae is fermented due to which butanol is produced. by this process, bio-ethanol can also be produced.

199. Which of the following fuel cannot be used in producing nuclear energy?
A. plutonium
B. uranium
C. tritium
D. deuterium

Answer: D deuterium
Explanation: since deuterium contains two electrons in its shell, it becomes difficult to break into a fully filled octet, due to which it cannot be used as a fuel in nuclear energy.

200. How does the texture of coal changes with its maturity?
A. becomes hard, less brittle and moderately tough
B. becomes hard, more brittle and more tough
C. becomes hard, more brittle and less tough
D. no change

Answer: B becomes hard, more brittle and more tough
Explanation: the texture of coal tends to the layer present on the coal and its maturity is from lignite to anthracite. the number of layers from lignite to anthracite increases due

201. On what factors does the specific gravity of coal depends?
A. its calorific value and ash content
B. its ignition temperature and calorific value
C. type of coal and ash content
D. type of coal and calorific value

Answer: C type of coal and ash content
Explanation: specific gravity is the ratio of the density/mass of a substance to the density/mass of reference substance. the total ash content represents its mass and

202. Which of the coal have the best heating values in terms of volatile matter?
A. containing 20% volatile matter
B. containing 60% volatile matter
C. containing 30% volatile matter
D. containing 50% volatile matter

Answer: A containing 20% volatile matter
Explanation: coals containing high volatile matter produces long and smoky flame due to which its heating value decreases. semi- bituminous coal has the highest heating value due to less volatiles content.

203. Which type of coals have the highest grindability index?
A. steam coals
B. gas coals
C. house coals
D. pulverised coals

Answer: D pulverised coals
Explanation: grindability is the ease with which a coal can be grounded. the grindability index of pulverised coal is about

204. How does the friability of the coal is tested?
A. drop shatter test
B. thermal cracking
C. knocking
D. proximate analysis

Answer: A drop shatter test
Explanation: friability is the tendency of the coal to break into pieces. the more the friability, the less will be the quality of coal. splint and cannel coal are less friable.

205. Which property of coal is tested in Audibert Arnu test?
A. bulk density
B. colour
C. caking and coking
D. texture

Answer: C caking and coking
Explanation: this method uses a dilatometer to find out the swelling properties of coal.

206. On which property of coal does the design of bunkers for the storage of coal depends?
A. specific gravity
B. bulk density
C. grindability
D. friability

Answer: B bulk density
Explanation: bunkers/coal bins are the containers in which the coal can be transported. bulk density is weight of soil present in coal. according to the bulk density

207. Phosphorous and sulphur content in the coal tend to make a metal brittle.
A. true
B. false

Answer: A true
Explanation: a coal should not contain high phosphorous and sulphur content because coal have a role in number of metallurgical operation due to which it affects the properties of metal and makes it brittle.

208. Which of the following is not a characteristic of coal?
A. weathering
B. slaking index
C. moisture content
D. bulk density

Answer: C moisture content
Explanation: moisture content represents the total vapours present inside the coal. moisture develops from the outside atmospheric conditions due to which it is not a characteristic of coal.

209. In determination of carbon and hydrogen by ultimate analysis, increase in weight of calcium chloride bulb represents
A. weight of water formed
B. weight of carbon dioxide formed
C. carbon
D. hydrogen

Answer: A weight of water formed
Explanation: the gaseous products of combustion are passed through two bulbs. one containing weighed amount of anhydrous calcium chloride which absorbs water other containing weighed amount of potassium hydroxide which absorbs carbon dioxide.

210. Hydrogen available for combustion is lesser than the actual one.
A. true
B. false

Answer: A true
Explanation: oxygen is present in combined form with hydrgen in the coal. it is very difficult to break hydrogen-oxygen bond and hence, that combined form of hydrogen is not available for combustion. thus, free hydrogen available for combustion is lesser than the actual one.

211. Good quality of coal should have % of oxygen.
A. low
B. high
C. 100
D. 0

Answer: A low
Explanation: good quality of coal should have less % of oxygen because increase in 1% oxygen content decreases calorific value approximately by 1.7%. ideal fuel should have high calorific value and hence, less

212. Percentage of ash by analysis of coal is given by
A. (weight of residue/weight of sample) × 100
B. (weight of sample – weight of residue) × 100
C. (weight of sample – weight of residue)/weight of sample × 100
D. (weight of residue – weight of sample) × 100

Answer: A (weight of residue/weight of sample) × 100
Explanation: ash is weight of residue obtained after complete combustion of 1 g of coal at 700‐750°c. ash in % is given by, %a

213. In coal, Sulphur is usually present in the extent of
A. 0.5-3%
B. 90-95%
C. 70-75%
D. 80-85%

Answer: A 0.5-3%
Explanation: sulphur is generally present in the extent of 0.5 to 3% and is usually derived from ores like gypsum, iron pyrites, etc. high percentage of sulphur in coal is undesirable to be used for making coke in the iron industry since it affects the quality and properties of steel.

214. In ultimate analysis, %hydrogen is given by
A. (increase in weight of cacl2 tube×2×100 / weight of coal sample taken×18)
B. (increase in weight of koh tube×2×100 / weight of coal sample taken×18)
C. (increase in weight of cacl2 tube×4×100 / weight of coal sample taken×18)
D. (increase in weight of koh tube×4×100 / weight of coal sample taken×18)

Answer: A (increase in weight of cacl2 tube×2×100 / weight of coal sample taken×18)
Explanation: %hydrogen= (weight of hydrogen/weight of coal sample taken) × 100 in ultimate analysis of coal,

215. is the weight of residue obtained after burning a weighed amount of dry coal.
A. ash
B. volatile matter
C. moisture
D. carbon

Answer: A ash
Explanation: ash is an unwanted matter and non-combustible which is the residue left after all combustible substances are burnt off.

216. In proximate analysis of coal, %fixed carbon =
A. 100 – % (ash + volatile matter + moisture)
B. 100 – % (ash + moisture)
C. 100 – % (ash + moisture) + %volatile matter
D. 100 – % (moisture + volatile matter)

Answer: A 100 – % (ash + volatile matter + moisture)
Explanation: in proximate analysis of coal, firstly percentage of ash, volatile matter and moisture is found out. percentage of fixed carbon can be found out by subtracting the above percentages from 100 since coal consists of ash, moisture, volatile matter and fixed carbon.

217. What is the primary component of crude oil?
A. sulfur
B. carbon
C. hydrogen
D. nitrogen

Answer: B carbon
Explanation: crude oil is greenish brown and viscous oil found on the earth’s surface. it is primarily composed of hydrocarbons (79.5- 87.1%) followed by hydrogen (11.5-14.8%), sulfur (0.1-3.5%), and nitrogen and oxygen (0.1-0.5%).

218. How is crude oil separated?
A. crystallization
B. fractional distillation
C. decantation
D. sublimation

Answer: B fractional distillation
Explanation: crude oil is usually suspended on a layer of brine with a deposit of gas over it. this form is usually not preferred for any

219. What type of gas is LPG?
A. gasoline
B. kerosene
C. uncondensed
D. heavy oil

Answer: C uncondensed
Explanation: crude oil separated by fractional distillation is made into a number of products such as uncondensed gas. this gas is used for domestic and industrial applications by the name liquefied petroleum gas (lpg).

220. Which fuel/oil is used for obtaining gasoline?
A. kerosene
B. diesel
C. heavy
D. naphtha

Answer: C heavy
Explanation: heavy oil is a crude oil product used for acquiring gasoline by cracking process. it has a boiling temperature range of 250-320oc. this gasoline, in turn, is used for motor fuel.

221. Which of the following is not used as a lubricant?
A. lubricating oil
B. grease
C. asphalt
D. petroleum jelly

Answer: C asphalt
Explanation: lubricating oils and grease are primarily used as lubricating agents, while petroleum jelly is used for lubrication as well as in cosmetics and medicines. asphalt is a residue type product used for waterproofing of roofs and to make roads.

222. What is the function of petroleum coke?
A. lubrication
B. in candles
C. as fuel
D. as solvent

Answer: C as fuel
Explanation: petroleum coke is a carbon-rich group of products used as fuel. petcoke is one such type of the product, which is derived from cracking process. raw coke is referred to as green coke.

223. Carbon black and hydrogen can be manufactured using
A. natural gas
B. coal gas
C. oil gas
D. water gas

Answer: A natural gas
Explanation: natural gas is obtained from wells in oil-rich regions. it acts as a domestic fuel and is also used to manufacture carbon black and hydrogen. carbon black is used as a filler for rubber, whereas hydrogen is used in ammonia synthesis.

224. Coal gas is attained from to a process carried out at
A. 300oc
B. 700oc
C. 900oc
D. 1300oc

Answer: D 1300oc
Explanation: coal gas is produced by heating the coal at 1300oc when there is a lack of air. it is usually done in coke ovens or gas making retorts. this gas is colorless and is lighter than air.

225. Oil gas is obtaining by the cracking of
A. kerosene oil
B. diesel oil
C. heavy oil
D. gasoline

Answer: A kerosene oil
Explanation: creating oil gas is a permanent process. this is done by breaking of complex hydrocarbons of kerosene into simpler forms. this process is known as cracking. oil finds its application as a laboratory gas.

226. Which of these gases is used for heating open-hearth furnaces?
A. oil gas
B. producer gas
C. biogas
D. water gas

Answer: B producer gas
Explanation: producer gas is known as a combination of combustible gases, carbon monoxide, and hydrogen. this gas finds its application in the heating of open-hearth furnaces, muffle furnaces, and retorts used in the production of coke. also, it can be used as a reducing means in metallurgical practices.

227. How is biogas prepared?
A. decantation
B. filtration
C. fermentation
D. sublimation

Answer: C fermentation
Explanation: biogas is a cheap and convenient fuel used for cooking and for lighting. it is prepared by the anaerobic fermentation of cattle dung.

228. Which type of coal is used in Bergius process?
A. anthracite coal
B. steam coal
C. pulverised coal
D. gas coal

Answer: D gas coal
Explanation: bergius process is used to produce synthetic gasoline form low ash pulverised coal. this coal is finely divided into powder and is converted into a paste.

229. Which substance is mixed with the pulverised coal in the Bergius process?
A. sulphuric acid
B. heavy oil and catalyst
C. heavy oil
D. catalyst

Answer: B heavy oil and catalyst
Explanation: the paste of pulverised coal is mixed with a heavy oil and a catalyst. nickel oleate is used as a catalyst in this process.

230. At what temperature does the Bergius process is carried out?
A. 200-300 0c
B. 700-800 0c
C. 350-500 0c
D. 0-150 0c

Answer: C 350-500 0c
Explanation: the temperature of converter is set to about 350-500 0c and a pressure of about 200-250 atmospheres where the paste of coal meets hydrogen. the fischer-tropsch process is carried out at 200-300 0c.

231. Which product is obtained from the converter in the Bergius process?
A. hydrocarbons
B. olefins
C. fuel oil
D. gasoline

Answer: A hydrocarbons
Explanation: the combination of hydrogen with the carbon framework of the coal yields various hydrocarbons from wax to gases. the high molecular weight hydrocarbons are decomposed further at the high temperature prevailing in the converter giving lower hydrocarbons.

232. Same catalyst is used for production of oil in the Bergius process as used in the production of hydrocarbons.
A. true
B. false

Answer: B false
Explanation: for production of gasoline, oils produced in the first stage of the process are subjected to further hydrogenation in the presence of different catalyst. nickel oleate is not used for this process.

233. Which compounds are rich in gasoline obtained from the Bergius process?
A. tetraethyl lead
B. ethanol
C. olefins
D. aromatic compounds

Answer: D aromatic compounds
Explanation: the gasoline obtained from the bergius process is rich in aromatic and branched-chain hydrocarbons. tetraethyl lead is an anti-knocking agent which is used for increasing the octane number.

234. What happens to the middle oil fraction in the Bergius process?
A. the oil is converted into olefins
B. the oil is converter into paraffin
C. the oil is converted into gasoline
D. the oil is converted into hydrocarbons

Answer: C the oil is converted into gasoline
Explanation: the middle oil fraction is subjected to hydrogen in the presence of a catalyst to produce gasoline. same process is carried out in the top fraction of the reactor. the heavy oil fraction is recycled to make a paste with a fresh batch of coal powder.

235. Which undesirable compound is present in gasoline?
A. sulphur compounds
B. phosphorous compounds
C. chloride compounds
D. magnesium compounds

Answer: A sulphur compounds
Explanation: the gasoline obtained by any process contains some sulphur compounds and unsaturated hydrocarbons, which get oxidized and polymerised to gums and sludge’s. hence it has to be refined by chemical processes.

236. How much percentile of sulphuric acid is treated with gasoline for the removal of its impurities?
A. 99 %
B. 60 %
C. 80 %
D. 40 %

Answer: C 80 %
Explanation: the impure gasoline is treated with cold 80 % sulphuric acid. this does not react with paraffin, naphthenes and aromatic compounds. it reacts with unsaturated hydrocarbons to produce alcohols and ethers.

237. Removal of gaseous impurities like methane, ethane, propane and butane from gasoline is called as
A. stabilization of gasoline
B. sweetening of gasoline
C. doping of gasoline
D. blending of gasoline

Answer: A stabilization of gasoline
Explanation: the stabilization of gasoline is achieved by passing the impure gasoline into a fractionating tower having 49 plates. the lower plates are heated by steam, while the gasoline is introduced near the upper plates.

238. Which of the following compound readily goes under the process of knocking?
A. 2-ethly butane
B. n-heptane
C. benzene
D. toluene

Answer: B n-heptane
Explanation: n-heptane is a straight chain hydrocarbon which knocks readily and hence its octane number is zero. presence of straight chain hydrocarbon in gasoline reduces its rate of combustion.

239. Which of the following compound is considered for calculating the cetane number?
A. α-methyl naphthalene
B. n-hexane
C. iso-octane
D. cetane molecule

Answer: D cetane molecule
Explanation: cetane, c16h34, is a saturated hydrocarbon that has a very short ignition lag as compared to any commercial diesel fuel.

240. What should be the cetane number of middle speed diesel engine?
A. at least 35
B. at least 25
C. at least 65
D. at least 45

Answer: A at least 35
Explanation: the cetane number of high speed diesel engine should be at least 45, that of middle speed diesel engine should be at least 35 and that of low speed diesel engine should be at least 25.

241. The knocking characteristic of gasoline fuel are expressed in terms of cetane number.
A. true
B. false

Answer: B false
Explanation: the knocking characteristics of diesel fuel are expressed in terms of cetane number and that of gasoline fuel is expressed in terms of octane number. the molecule with the highest octane number has a least cetane number.

242. Which of the following substance is used to decrease knocking in diesel fuel?
A. tetra ethyl lead
B. benzene
C. sodium hydroxide
D. acetone peroxide

Answer: D acetone peroxide
Explanation: the knocking in diesel fuel can be reduced by adding substances like ethyl nitrite, ethyl nitrate, isoamyl nitrate etc. this process also increases the cetane number of diesel fuel.

243. Which of the following is used to reduce the surface tension in diesel fuel?
A. chemical additives
B. inhibitors
C. poly hydrocarbon
D. dopes

Answer: A chemical additives
Explanation: chemical additives are used to reduce surface tension thus promoting the formation of finer spray. inhibitors are used to delay or prevent gum formation. poly hydrocarbons are used to preserve the fluid properties.

244. By which process does the knocking starts in diesel engine?
A. due to sudden spontaneous combustion of last portion of fuel
B. due to delay in spontaneous combustion of last portion of fuel
C. due to the rise in temperature of diesel engine
D. due to the parts of diesel engine

Answer: B due to delay in spontaneous combustion of last portion of fuel
Explanation: due to the presence of impurities in diesel, its spontaneous combustion of the last portion of fuel takes some time. due to this their produces an uneven sound in the engine which is called knocking.

245. Which of the following exhaust gas produces least harmless components after its combustion?
A. carbon monoxide
B. ethyne
C. nox
D. n2

Answer: D n2
Explanation: gases produced by the compression ignition engines are said to be exhaust gases. this engines operate with air- fuel ratios of 14:1 on load and 70:1 on idling.

246. Which of the following has the highest cetane number?
A. n-heptane
B. n-hexane
C. n-pentane
D. n-butane

Answer: A n-heptane
Explanation: n-heptane has maximum branched atom due to which it has the highest cetane number of all. this fuel is good for diesel engines.

247. Choose the correct statement, detonation can be controlled by
A. varying compression ratio
B. using lean mixture
C. retarding the spark timing
D. reducing the r.p.m

Answer: C retarding the spark timing
Explanation: detonation can be controlled by retarding the spark timing.

248. The ash content in diesel oil should be not be more than
A. 1%
B. 5%
C. 0.1%
D. 0.01%

Answer: D 0.01%
Explanation: the ash content in diesel oil should be not be more than 0.01% while sulphur content in diesel engine oil should not be more than 1%.

249. Which of the following is a disadvantage of gaseous fuel?
A. gaseous fuels are very difficult to operate
B. gaseous fuels are highly inflammable
C. gaseous fuels cannot be ignited instantly
D. they produce lot of smoke on combustion

Answer: B gaseous fuels are highly inflammable
Explanation: the particles in gaseous fuels are separated from each other, due to which their combustion becomes very easy. this increases the inflammability of the gaseous fuel. special care should be taken to avoid fire hazards.

250. Which of the following is a primary gaseous fuel?
A. water gas
B. oil gas
C. refinery gas
D. liquefied petroleum gas

Answer: D liquefied petroleum gas
Explanation: primary gaseous fuel are those, which are already present in nature and secondary gaseous fuels are those which are obtained from primary gaseous fuels. natural gas is also a primary gaseous fuel.

251. Which of the following compound is present in natural gas?
A. urea
B. benzoyl peroxide
C. methane
D. sulphonic acid

Answer: C methane
Explanation: natural gas is mainly composed of methane and small quantities of ethane and other hydrocarbons. urea consists of nitrogen due to which it is not present in natural gas.

252. Which type of natural gas is called wet natural gas?
A. containing lower hydrocarbon with more ethane
B. containing higher hydrocarbon with more ethane
C. containing lower hydrocarbon with more methane
D. containing higher hydrocarbon with more methane

Answer: D containing higher hydrocarbon with more methane
Explanation: if higher hydrocarbons are present along with methane, then the natural gas is called “rich” or “wet” natural gas. it is also called “marsh gas” because it majorly contains methane.

253. Which of the following natural gas has the highest ignition temperature?
A. natural gas obtained from oil fields
B. natural gas obtained from coal fields
C. natural gas obtained from rocks
D. natural gas obtained from sea

Answer: C natural gas obtained from rocks
Explanation: the natural gas produced from rocks by the diffusion of oil constituents a gas field that may be under high pressure. due to this high pressure, the flow potential of gas increase, which produces static electricity and increases the ignition temperature which is hazardous for us.

254. How much percentile of propane is present in natural gas?
A. 5.5 %
B. 3.7 %
C. 1.8 %
D. 0.5 %

Answer: B 3.7 %
Explanation: at an average 88.5 % of methane is present in natural gas. 5.5 % of ethane, 3.7 % of propane and 1.8 % of butane are present in natural gas. the higher hydrocarbons are present at about 0.5 %.

255. H2S is not present in natural gas.
A. true
B. false

Answer: B false
Explanation: h2s is present in small quantity in natural gas. if it is present in an appreciable amount, then it is called as “sour” natural

256. Which of the following process is used to recover vapours of liquid hydrocarbons in wet natural gas?
A. evaporation
B. distillation
C. cracking
D. adsorption

Answer: D adsorption
Explanation: the vapours of liquid hydrocarbons can be recovered by condensation, absorption in oil and by adsorption on charcoal, silica or alumina gel. the liquid so recovered is called casinghead gasoline.

257. Gaseous fuel is most suited for IC engine since physical delay is almost
A. zero
B. more
C. less
D. none of the mentioned

Answer: A zero
Explanation: as compared to other fuels there is almost no delay in gaseous fuel and for this purpose it is preferred the most.

258. Advantage of hydrogen as an IC engine fuel
A. high volumetric efficiency
B. low fuel cost
C. no hc and co emissions
D. none of the mentioned

Answer: C no hc and co emissions
Explanation: the main advantage of hydrogen as an ic engine fuel is that there is no hc and co emissions.

259. Major constituent of natural gas is
A. ethane
B. methane
C. butane
D. propane

Answer: B methane
Explanation: only methane is the major constituent of natural gas.

260. At normal ambient temperature and atmospheric pressure, in which form LPG is obtained?
A. solid
B. gaseous
C. liquid
D. solid-liquid

Answer: B gaseous
Explanation: lpg is a certain mixture of light hydrocarbons derived from petroleum. at normal temperature and pressure it is in gaseous state and later on it is condensed to the liquid state by the application of moderate pressure.

261. Under which compound name does the liquid petroleum gas (LPG) are sold?
A. urea
B. ethylene
C. benzoyl peroxide
D. butane

Answer: D butane
Explanation: propane and butane are present in the largest amounts in lpg. small quantities of ethane, pentane, ethylene and pentene are also present. under trade names it is represented as hp, bharat gas and indian gas in india.

262. By which process only saturated hydrocarbons are obtained in LPG?
A. straight distillation
B. thermal cracking
C. hydrocracking
D. reforming

Answer: A straight distillation
Explanation: the lpg obtained from heavier hydrocarbons by straight distillation process only contains saturated hydrocarbons, where as the lpg obtained from thermal cracking or hydrocracking contains both saturated and unsaturated hydrocarbons.

263. Which type of LPG is mostly produced in Indian refineries?
A. grade a
B. grade b
C. grade c
D. grade d

Answer: B grade b
Explanation: according to the bureau of indian standards, grade b contains a mixture of butane and propane. this type of lpg are supplied for domestic uses.

264. According to the Bureau of Indian Standards which type of LPG only contains butane in them?
A. grade a
B. grade b
C. grade c
D. grade d

Answer: A grade a
Explanation: grade a consist predominantly of butanes, butylene or mixture of butanes and butylene’s. this type of lpg are most suitable for use due to their moderate rate of combustion.

265. In which regions does the LPG containing propane are found?
A. hotter region
B. monsoon region
C. colder region
D. terrestrial region

Answer: C colder region
Explanation: lpg containing propane is found in the colder region due to less temperature and pressure conditions. these are found towards the north pole of the earth.

266. Liquid petroleum gas (LPG) is corrosive to steel.
A. true
B. false

Answer: B false
Explanation: the sulphur and phosphorous content in lpg are very low due to which these are non-corrosive to steel. this type of fuel is used in industries having large steel supplies.

267. What happens when LPG is inhaled in large concentrations?
A. it kills a person
B. it increases a person’s eye sight
C. it does not have any effect on person’s health
D. it causes a little anaesthesia

Answer: D it causes a little anaesthesia
Explanation: butane and propane are present in large amount are lpg. if inhaled in large quantities, it becomes anaesthetic which can cause a person to fall after some time.

268. What is the odour of Liquid Petroleum Gas (LPG)?
A. it is odourless
B. fruity smell
C. undesirable odour
D. alcoholic smell

Answer: A it is odourless
Explanation: lpg does not have a characteristic odour. highly odorous compounds such as ethyl and propyl merchants are deliberately mixed so as to

269. In which type of industries LPG is used as a fuel?
A. steel industries
B. plastic industries
C. in the production of olefins
D. in the production of coal gas

Answer: C in the production of olefins
Explanation: lpg is used as a feedstock for the manufacturing of olefins by the process of pyrolysis. it is also used as a domestic fuel for internal combustion engines.

270. Power alcohols contains
A. 50-60% of petrol
B. 70-80% of petrol
C. 50-60% of ethanol
D. 70-80% of ethanol

Answer: B 70-80% of petrol
Explanation: when ethyl alcohol is used in internal combustion engines then it is called as power. so, it contains 70-80% of petrol and 20-25% of ethanol.

271. Alcohol can absorb
A. traces of water
B. traces of impurities
C. traces of dust
D. traces of carbon

Answer: A traces of water
Explanation: alcohol has the power to absorb the traces of water present in petrol as it dissolves in water.

272. Ethyl alcohol reduces the
A. oxygen emissions
B. efficiency
C. polluting emissions
D. nitrogen emissions

Answer: C polluting emissions
Explanation: ethyl alcohol contains nascent oxygen atoms that reduce the pollutants like co and other hydro carbons.

273. Power alcohol is than petrol.
A. bad product
B. less efficient
C. costlier
D. cheaper

Answer: D cheaper
Explanation: power alcohol is cheaper than petrol. it is the main advantage of the power alcohols made them to be fuels.

274. Main disadvantage of the power alcohol is
A. starting troubles
B. more cost
C. increases foreign currency
D. increases octane number of petrol

Answer: A starting troubles
Explanation: the main disadvantages of the power alcohols are starting troubles due to the high surface tension and atomization.

275. What is the colour of the bio diesel?
A. orange
B. light yellow
C. dark orange
D. light brown

Answer: B light yellow
Explanation: the bio diesel is light yellow in colour. most of the power alcohols are yellow in colour as they are hydrocarbons.

276. Natural gas contains
A. methane=70-90%
B. benzene=40-30%
C. hydrogen=50%
D. methane=80-40%

Answer: A methane=70-90%
Explanation: the composition of natural gas is: methane=70-90%; benzene=5-10%; co+carbon dioxide=remainder.

277. The calorific value of LPG is
A. 34800kcal/m3
B. 84000kcal/m3
C. 278000kcal/m3
D. 29000kcal/m3

Answer: C 278000kcal/m3
Explanation: the calorific value of the lpg is more than that of the natural gas. it is about 278000kcal/m3. so, it is more efficient than the natural gas.

278. Boiling point of LPG is
A. 546k
B. 373k
C. above room temperature
D. below room temperature

Answer: D below room temperature
Explanation: lpg has the property of fast ignition and it needs very less amount of energy to burn that is the heat supplied is very low about the temperature less than that if room temperature.

279. CNG has high auto-ignition temperature of
A. 813k
B. 993k
C. 1163k
D. 1273k

Answer: A 813k
Explanation: cng also have high auto ignition energy and has a calorific value of 900 kj/mole. its auto ignition temperature is about 813k.

280. To calculate HCV of the fuel, the products of combustion are cooled down to
A. 600f
B. 700f
C. 400f
D. 200f

Answer: A 600f
Explanation: the products of combustion are cooled down to 600f or 150c that is room temperature. the hydrogen gas gets converted into steam.

281. When the coal is completely burnt in air, then the maximum temperature reached is called
A. calorific value of coal
B. gross calorific value
C. calorific intensity of coal
D. net calorific value

Answer: C calorific intensity of coal
Explanation: calorific value of coal is defined as the amount of heat liberated during combustion of fuel completely. gross calorific value or hcv means the total heat liberated after combustion of fuel and

282. The Bomb calorimeter is used to determine the calorific value of
A. solids and liquid fuels
B. solid and gaseous fuels
C. liquid fuels that can be easily vaporized
D. solid fuels only

Answer: A solids and liquid fuels
Explanation: in bomb calorimeter, we can find the calorific value of both solid and gas fuels. in boy’s calorimeter we can fin calorific value for gaseous and easily vaporized liquid fuels.

283. Which of the following fuel gas will have the highest calorific value?
A. water gas
B. bio gas
C. producer gas
D. natural gas

Answer: D natural gas
Explanation: natural gas produces a high amount of heat when compared to the other three gases. water gas and producer gas are synthetic fuels and natural gas natural fuel.

284. On which property of fuel it’s calorific value is based?
A. specific heat
B. efficiency
C. cost
D. ignition temperature

Answer: B efficiency
Explanation: the calorific value is the total amount of heat liberated by complete combustion a unit amount of fuel, which is the total efficiency of the fuel.

285. What is the unit of calorific value in fps(foot pound sec)?
A. gram calorie (g cal)
B. pound calorie
C. british thermal unit/ft3
D. calorie/gram2

Answer: B pound calorie
Explanation: b.t.u. is the amount of heat required to rise the temperature of 1 lb of water through 1 0f. centigrade heat unit (chu) can also be used in fps system.

286. At how much temperature does the products of combustion should be cooled down to get Gross Calorific Value?
A. 288 k
B. 315 k
C. 390 k
D. 350 k

Answer: A 288 k
Explanation: at 288 k the products are cooled down, so as to get exact gross calorific value. it can be cooled down till room temperature.

287. What happens to the hydrogen present in fuel for calculating gross calorific value?
A. it combines with carbon to form methane
B. it combines with chlorine to form hydrochloric acid
C. it combines with oxygen to form hydrogen per oxide
D. it gets converted into steam

Answer: D it gets converted into steam
Explanation: after combustion of hydrogen, it gets converted into water vapour which then settles down as steam. after this process the products of combustion are cooled down.

288. How does the latent heat of condensation is included in gross calorific value?
A. by the steam produced by the combustion of hydrogen
B. by the combustion of products other than carbon and hydrogen
C. by the combustion of carbon
D. by the total heat produced in the system

Answer: A by the steam produced by the combustion of hydrogen
Explanation: the steam generated after combustion gets condensed into water and latent heat is evolved. the latent heat so liberated is included in gross calorific value.

289. Net Calorific Value is greater than Gross Calorific Value.
A. true
B. false

Answer: B false
Explanation: ncv = [gcv – 0.09%h×587] cal/gm, since both gcv and % h are positive the value of ncv will be less than gcv.

290. Which of the following properties a good fuel should have?
A. low calorific value
B. moderate calorific value
C. high calorific value
D. high ignition temperature

Answer: C high calorific value
Explanation: calorific value is the total amount of heat liberated by complete combustion of fuel, therefore the more the calorific value will be, the good the fuel will be.

291. Which of the fuel has the highest calorific value?
A. butane
B. wood
C. kerosene
D. natural gas

Answer: A butane
Explanation: the calorific value of butane is 118 mj/kg, this is due to the saturation of carbon bonding in butane, where as the calorific value of wood is lowest which is 16 mj/kg.

292. How should be the ignition temperature of an ideal fuel?
A. moderate
B. low
C. very low
D. very high

Answer: A moderate
Explanation: the lowest temperature to which the fuel must be preheated so that it starts burning smoothly is called ignition temperature. low ignition temperature can cause fire hazards during storage and transportation of fuel. in case of high ignition temperature, there might be some difficulty during ignition of fuel. so, an ideal fuel should have moderate ignition temperature.

293. Fuel should have low moisture content.
A. true
B. false

Answer: A true
Explanation: moisture if present in the fuel, reduces the heating value of the fuel. this ultimately leads to loss of money as moisture is paid at the same rate as that of fuel. hence,

294. In which type of fuel given below, risk of fire hazard is greatest?
A. solid fuel
B. gaseous fuel
C. liquid fuel
D. peat

Answer: B gaseous fuel
Explanation: risk of fire hazards in gaseous fuel is very high because these fuels are highly inflammable. peat is a type of solid fuel.

295. is easy in terms of storage.
A. solid fuel
B. liquid fuel
C. gaseous fuel
D. natural gas

Answer: A solid fuel
Explanation: solid fuel is easy to store. liquid fuel should be stored in closed containers only. gaseous fuel must be stored in leak proof storage tanks. natural gas is a type of gaseous fuel.

296. Rate of combustion should be
A. very rapid
B. moderate
C. slow
D. very slow

Answer: B moderate
Explanation: if the rate of combustion is low, then a part of heat liberated may get radiated instead of raising the temperature. if combustion rate is too high, reaction gets out of control. so, good fuel should have moderate rate of combustion.

297. Handling cost of solid fuel is high compared to liquid and gaseous fuel.
A. true
B. false

Answer: A true
Explanation: handling cost of solid fuel is high because labour is required in their storage, transport, etc. whereas liquid and gaseous fuel can be easily transported through pipes.

298. The lowest temperature to which the fuel must be preheated so that it starts burning smoothly is called temperature.
A. ignition
B. combustion
C. boiling point of fuel
D. preheating

Answer: A ignition
Explanation: the lowest temperature to which the fuel must be preheated so that it starts burning smoothly is called ignition temperature. an ideal fuel should have moderate ignition temperature.

299. Which of the following fuel cannot be used in the internal combustion engine?
A. gasoline
B. diesel
C. fuel oil
D. anthracite coal

Answer: D anthracite coal
Explanation: anthracite is a type of solid fuel. it is not possible to use solid fuel in internal combustion engine. only liquid or gaseous fuels are possible to be used in the internal combustion engine.

300. In which of the following, smoke is produced maximum?
A. solid fuel
B. liquid fuel
C. gaseous fuel
D. coal gas

Answer: A solid fuel
Explanation: in solid fuel, smoke is invariably produced. in liquid fuel burning is clean however high carbon and aromatic

301. Auto-ignition temperature is
A. maximum temperature to which oil is heated in order to give off inflammable vapour in sufficient quantity to ignite momentarily when bought in contact with a flame
B. that at which it catches fire without external aid
C. indicated by 90% distillation temperature
D. none of the mentioned

Answer: B that at which it catches fire without external aid
Explanation: auto-ignition temperature is defined as that temperature at which it catches fire without external aid while volatility of diesel fuel is indicated by 90% distillation temperature.

302. Ignition lag is
A. the time taken by fuel after injection to reach upto auto-ignition temperature
B. time before actual fuel injection and the pump plinger starts to pump fuel
C. time corresponding to actual injection and top dead center
D. none of the mentioned

Answer: A the time taken by fuel after injection to reach upto auto-ignition temperature
Explanation: none.

303. Ignition quality of diesel fuel oil is expressed by an index called
A. octane number
B. cetane number
C. calorific value
D. none of the mentioned

Answer: B cetane number
Explanation: cetane number is defined as the ignition quality of diesel fuel oil is expressed by an index.

304. In presence of which gas is the fuel burnt to generate energy in the form of heat?
A. oxygen
B. hydrogen
C. methane
D. nitrogen

Answer: A oxygen
Explanation: the fuel is burnt in the presence of oxygen to generate energy in the form of heat. this heat energy can be used for electrical power generation in steam power plants and for propelling ships, automobiles and locomotives, etc.

305. Which are the main constituents of fuel from given options?
A. carbon and nitrogen
B. oxygen and hydrogen
C. carbon and hydrogen
D. helium and oxygen

Answer: C carbon and hydrogen
Explanation: carbon and hydrogen are the main constituents of a fuel. in addition to them, fuel also contains sulfur, oxygen and nitrogen in minimal quantities. depending on the fuel, the percentage of carbon ranges from 50-95%, hydrogen (h2) 2-6%, oxygen (o2) 2-

306. Which fuel is used widely in steam power plants?
A. oil
B. gas
C. coal
D. petroleum

Answer: C coal
Explanation: coal is the oldest form of fuel and is still used in a large scale throughout the world by steam power plants as well as all power generation plants. coal is a heterogeneous compound and its constituents are always carbon, hydrogen, oxygen, sulfur, nitrogen and certain mineral non combustibles.

307. What is the phenomenon of the formation of coal called?
A. metamorphism
B. diagenis’
C. photosynthesis
D. protolith

Answer: A metamorphism
Explanation: the phenomenon by which the buried vegetation consisting wood, grass, shrubs etc, transformed into coal is known as metamorphism. the nature of coal will depend upon the type of vegetation buried and nature and duration of metamorphism.

308. On what basis is the coal classified?
A. period of formation
B. depending on capacity to burn
C. region/area where is it formed
D. physical and chemical composition

Answer: D physical and chemical composition
Explanation: the coal is classified on the basis of its physical and chemical composition. the proximate and ultimate analyses are the common tests which are used to find the commercial value of the coal. the proximate analysis gives characteristics of coal such as percentage of moisture, ash and volatile matter. analysis of coal gives an indication about fusion temperature and heating value of the coal.

309. What is the use of electrostatic precipitations in steam power plant?
A. to remove the steam
B. to draw the coal powder into boiler
C. to remove the feed water
D. to remove fly ash

Answer: D to remove fly ash
Explanation: the electrostatic precipitators are extensively used in the steam power plant for removal of fly ash from the electric utility boiler emission. since the water inside the boiler is converted into steam, the fire for converting is fuelled by burning the coal which produces high amount of fly ash, so that the ash’ can be reused. the use of electrostatic precipitators is growing rapidly because of the new strict air code and environmental laws. an electrostatic can be designed to operate at any desired efficiency.

310. Why is ‘make-up water’ added to drum continuously?
A. to remove the impurities in tube
B. to replace the water that has been converted into steam
C. to keep the system cool externally
D. to compensate for water loss trough blow down

Answer: D to compensate for water loss trough blow down
Explanation: make-up water is added to compensate for the losses of water incurred by blow downs or leakages occurring in boiler, and also to maintain desired water level in boiler steam drum. blow down and

311. What causes failure of boiler tube?
A. heating the tubes, when desired water level is not maintained
B. induced pressure in the water
C. over use of boiler
D. hardness of water

Answer: D hardness of water
Explanation: hardness of water causes failure of boiler tube. hard water consists of calcium and magnesium salts. hardness in water will form deposits on the tube water surfaces which will lead to overheating and failure of tubes. thus the salts have to be removed from the water.

312. Which of the following is the correct condition for the efficient combustion of coal?
A. coal should be of high calorific value
B. intimate mixing of air with the combustible matter
C. the ignition temperature should be high
D. the volatile matter should be low

Answer: B intimate mixing of air with the combustible matter
Explanation: for efficient combustion, it is essential that the coal and its distillation products are brought into intimate contact with sufficient quantity of air to burn all combustible material. also, sufficient time should be allowed to complete the combustion process.

313. Which of the following furnace is best suitable for the efficient combustion of coal?
A. blast furnace
B. pudding furnace
C. open hearth furnace
D. boiler furnace

Answer: D boiler furnace
Explanation: this type of furnaces are used for efficient combustion of coal since these convert the heat into thermal energy which are then used for generation of power.

314. Which of the following is calculated by flue gas analysis?
A. amount of air used in combustion
B. rate of combustion
C. time required for combustion
D. amount of air present after combustion

Answer: A amount of air used in combustion
Explanation: the only practical way for determining the amount of air used in furnace is to analyse the flue gas for the constituents co2, co an o2. the control of air is by means of dampers.

315. What happens when carbon monoxide is obtained in flue gas analysis?
A. combustion is complete
B. combustion does not take place
C. combustion is incomplete
D. it increases the rate of combustion.

Answer: C combustion is incomplete
Explanation: if the analysis shows the presence of free co, it means that the combustion is incomplete which calls for an intermediate increase in the amount of air used for combustion. also, a diminution in the rate of supply of coal is required.

316. What happens when too much excess air is supplied to the furnace in the process of combustion of coal?
A. there is a gain in heat in the furnace
B. no change occurs in the furnace
C. there is loss in heat in the furnace
D. the excess air escapes out

Answer: C there is loss in heat in the furnace
Explanation: in ordinary furnaces, 50 to 100

317. If both CO and O2, both are indicated in the appreciable amount in the flue gas analysis, which type of combustion is seen?
A. regular and non-uniform combustion
B. irregular and non-uniform combustion
C. regular and uniform combustion
D. irregular and uniform combustion

Answer: B irregular and non-uniform combustion
Explanation: if both co and o2 are present in an appreciable amount, then the combustion is irregular and non-uniform.

318. Short orsat apparatus gives more precise results than long orsat in the analysis of flue gas.
A. true
B. false

Answer: B false
Explanation: long orsat or precision model orsat is used for analysis of quite complicated mixtures and which gives very accurate

319. At what temperature does the CO is converted to CO2 in orsat apparatus for analysis of flue gas?
A. 280-295 0c
B. 250-265 0c
C. 350-365 0c
D. less than 100 0c

Answer: A 280-295 0c
Explanation: at the temperature range of 280-295 0c, the co is converted into co2. also the hydrogen present is oxidised to water. the diminution in the volume of gas sample indicates the volume of hydrogen.

320. Which of the following apparatus cannot be used for flue gas analysis?
A. ambler’s apparatus
B. hemple’s apparatus
C. able’s apparatus
D. bunte’s apparatus

Answer: C able’s apparatus
Explanation: able’s apparatus is used for calculation of flash point and fire point of an oil. flash point is the minimum temperature of oil, at which the vapours of oil produces flash in a burning match stick when brought close to the vapours of oil.

321. In which of the following process are Neutrons emitted?
A. inverse beta decay
B. nuclear fission
C. spontaneous fission
D. nuclear fusion

Answer: B nuclear fission
Explanation: nuclear fission is the process in which a heavy nucleus is split into two or more lighter nuclei. this result in decrease in mass and consequent exothermic energy and emission of neutrons take place. two to three neutrons are emitted per nucleuses which are known as fission elements.

322. Heavy nuclei must be such that they can be fissioned by neutrons of an energy such substance are called?
A. fission fragments
B. fission neutrons
C. fission species
D. fission elements

Answer: C fission species
Explanation: heavy nuclei must be such that they can be fissioned by neutrons of energy such substance are called fission species. all fission species should have long half lives so that the rate of decay is not so fast.

323. What happens when a neutron is absorbed by a nucleus of an atom of U235?
A. mass number of atom increases
B. one electron is let out
C. u236 isotope is formed
D. nucleus becomes unstable

Answer: C u236 isotope is formed
Explanation: when a neutron is absorbed by a nucleus of an atom u235, a u236 isotope is formed. this isotope is highly unstable which lasts for one millionth of a second and splits into two equal parts releasing energy of 200mev.

324. Who invented nuclear fission?
A. rutherford
B. hans bethe
C. otto hahn
D. marie curie

Answer: C otto hahn
Explanation: nuclear fission of heavy metals was discovered by german otto hahn on december 17, 1938 and was explained theoretically by lise meitner and her nephew otto robert frisch on 1939. frisch named frisch names the process by analogy with biological fission of living cells.

325. Atoms of different chemical elements that have the same number of nucleons are called as?
A. isobars
B. isotones
C. isomers
D. isotopes

Answer: A isobars
Explanation: atoms of different chemical elements that have the same number of nucleons are called as isobars. the term isobar was suggested by alfred walter

326. Most of the energy released in fission process is in process of
A. kinetic energy
B. thermal energy
C. light energy
D. heat energy

Answer: A kinetic energy
Explanation: most of the energy released is in the form of kinetic energy and is absorbed by fission products. the fission products formed are fission fragments, neutrons and electromagnetic or gamma radiation. as the fragments collide, the kinetic energy is converted into heat energy.

327. Combining of two light nuclei of low mass to produce a heavy nucleus is called
A. nuclear fusion
B. nuclear fission
C. spontaneous fission
D. double beta decay

Answer: A nuclear fusion
Explanation: nuclear fusion is the process which involves fusion of two light nuclei of low mass to produce a heavy nucleus which results in decrease of mass and release of enormous amount of energy. all atomic bombs prefer nuclear fission process.

328. What type of Reaction takes place in sun?
A. nuclear fusion
B. nuclear fission
C. spontaneous fission
D. double beta decay

Answer: A nuclear fusion
Explanation: nuclear fusion reaction takes place in sun as well as stars. the process is carried by proton-proton chain. the sun starts with protons, and through a series of steps, turns them into helium. every second 600

329. How many number of nuclei of hydrogen fuse in a series of reaction involving other particles that continually appear and disappear?
A. 1
B. 2
C. 3
D. 4

Answer: D 4
Explanation: four nuclei of hydrogen fuse in a series of reaction involving other particles that continually appear and disappear such as he3, nitrogen, carbon and other nuclei.

330. Why is it necessary to accelerate positively charged nuclei to high kinetic energies to cause fusion?
A. to overcome electrical repulsive forces
B. to result in high amount of energy in short period of time
C. to get the isobars and isotopes
D. to get a sustainable reaction

Answer: A to overcome electrical repulsive forces
Explanation: to cause fusion, it is necessary to accelerate positively charged nuclei to high kinetic energies to overcome electrical repulsive forces. this is done by rising their temperatures to hundreds of millions of degree resulting in plasma.

331. Fusion reactions are called
A. thermonuclear
B. thermoduric
C. thermo uric
D. compound reactions

Answer: A thermonuclear
Explanation: to eradicate repulsive forces temperature of positively charged nuclei is raised to millions of degree resulting in plasma. the plasma should be prevented from contacting the walls of the container confined for a period of time of the order of a second at a minimum density. fusion reactions are called thermonuclear because of the higher temperature requirement to trigger and sustain the reaction.

332. Which of the following element is readily available in the ordinary water?
A. cesium
B. thorium
C. deuterium
D. astatine

Answer: C deuterium
Explanation: deuterium used in fusion reaction is readily available in ordinary water (out of 6500 molecules). deuterium is also known as heavy hydrogen. the nucleus of deuterium is called as deuteron, contains one

333. How is tritium made from sea water?
A. by bombarding lithium
B. by bonding with carbon
C. by bombarding beryllium
D. by reacting with oxygen

Answer: A by bombarding lithium
Explanation: tritium is made by seawater by bombarding with lithium. lithium is a chemical element with atomic number: 3 and mass number: 6.941 u ± 0.002 u. because of its relative nuclear instability, lithium is less common in the solar system.

334. The atomic weight and atomic number of an element are A and Z respectively. What is the number of neutrons in the atom of that
A. 1
B. 2
C. 3
D. 6

Answer: C 3
Explanation: thermal nuclear reactors using enriched uranium as fuel contains a maximum of 6 percent fissile material i.e. u-235.

335. moderator is used in a fast breeder reactor.
A. heavy water
B. graphite
C. no
D. beryllium

Answer: C no
Explanation: a fast breeder reactor doesn’t employ any moderator.

336. Nuclides having the same atomic number are termed as?
A. isobars
B. isotones
C. isotopes
D. isomers

Answer: D isomers
Explanation: isomers are nuclides having the same atomic number.

337. Main source of is monazite sand.
A. uranium
B. polonium
C. halfnium
D. thorium

Answer: D thorium
Explanation: thorium is the main source of monazite sand.

338. Emission of β-particles during radioactive decay of a substance is from
A. nucleus
B. innermost shell
C. outermost shell
D. none of the mentioned

Answer: A nucleus
Explanation: emission of β-particles during radioactive decay of a substance is from the nucleus as all emissions are nuclear phenomenon.

339. A fertile material is the one, that can be
A. converted into fissile material on absorption of neutron
B. fissioned by either slow or fast neutrons
C. fissioned by slow (thermal) neutrons
D. fissioned by fast neutrons

Answer: A converted into fissile material on absorption of neutron
Explanation: a fertile material is the one, which can be converted into fissile material on absorption of neutron.

340. The half-life period of a radioactive element depends on its
A. temperature
B. pressure
C. amount
D. none of the mentioned

Answer: D none of the mentioned
Explanation: the half-life is independent of the mentioned factors.

341. Which is radioactive in nature?
A. helium
B. deuterium
C. tritium
D. heavy hydrogen

Answer: C tritium
Explanation: tritium is a radioactive element.

342. Which is the most commonly used nuclear fuel in boiling water reactor?
A. enriched uranium
B. plutonium
C. natural uranium
D. monazite sand

Answer: A enriched uranium
Explanation: enriched uranium is the most commonly used nuclear fuel in boiling water reactor.

343. Fuel for a nuclear reactor (thermal) is
A. uranium
B. plutonium
C. radium
D. none of the mentioned

Answer: A uranium
Explanation: uranium is the fuel for a thermal reactor.

344. The first underground nuclear test was conducted by India at
A. pokhran
B. kalpakkam
C. jaisalmer
D. narora

Answer: A pokhran
Explanation: pokhran had the very first underground nuclear test.

345. The best capable alternative source which can meet the future energy demand is
A. thermal power plant
B. nuclear power plant
C. hydroelectric power plant
D. geothermal power plant

Answer: B nuclear power plant
Explanation: demand of electrical energy is increasing at fast rate owing to booming increase in the population and industrial growth. the reserves of fossil fuel i.e., coal, oil and gas are fast depleting. there are many alternative sources of energy but they are not enough to supply such huge demand, only nuclear power plants are capable of doing that.

346. How much coal is required to generate energy equivalent to the energy generated by 1 kg of uranium?
A. 30000 tonnes of high grade coal
B. 300 tonnes of high grade coal
C. 10000 tonnes of high grade coal
D. 3000 tonnes of high grade coal

Answer: D 3000 tonnes of high grade coal
Explanation: one of the main attention for nuclear fuel is the huge amount of energy that can be released from a small quantity of active nuclear fuel. the energy obtainable by completely using 1 kg of uranium would give energy equivalent 3000 tons of high grade coal i.e. uranium has three millions times the energy of coal.

347. Nuclear fuel in reactor lasts for
A. more than 5 months
B. few weeks
C. few days
D. more than 5 years

Answer: D more than 5 years
Explanation: very small amount of nuclear fuel can produce very high amount of energy. nuclear fuel may remain in a reactor for more than 5 years.

348. Cost of nuclear fuel in nuclear power plant economics is considered as
A. running cost
B. maintenance cost
C. capital cost
D. development cost

Answer: C capital cost
Explanation: nuclear fuel in a nuclear reactor may remain for more than 5 years. so the cost of fuel injected initially is taken as capital cost and may be a few crore rupees.

349. Which of the following are not taken as operation and maintenance cost in economics of nuclear power plant?
A. taxes and insurance
B. salaries and wages of staff
C. cost of waste disposal
D. cost of processing materials

Answer: A taxes and insurance
Explanation: taxes and insurance are taken as fixed costs. salaries and wages of operation and maintenance staff, cost of waste disposal and cost of processing materials are the operation and maintenance cost.

350. What is the overall efficiency of nuclear power plant?
A. 20 to 25%
B. 25 to 30%
C. 30 to 40 %
D. 50 to 70 %

Answer: C 30 to 40 %
Explanation: the overall efficiency of a nuclear power plant is around 30 to 40%. efficiency is higher at high road factors. therefore, a nuclear power plant is always operated as a base load plant.

351. The land area required for installation of nuclear power plant is
A. more than thermal power plant
B. less than thermal power plant
C. equel to thermal power plant
D. depends on type of construction

Answer: C equel to thermal power plant
Explanation: nuclear power plants need less area as compared to any other plant of same generation capacity. a 2000mw nuclear power plant needs about 80 acres whereas the

352. All of the nuclear fuel reserve will be ended in about 400 years.
A. true
B. false

Answer: B false
Explanation: there are larger deposits of nuclear fuel available all over the world. therefore, such plants can ensure continued supply of electrical energy for thousands of years.

353. With respect to the load centre which location is suitable for stablishment of nuclear power plant?
A. load centre
B. near load centre but at reasonable distance
C. far away from load centre
D. near chemical industries

Answer: B near load centre but at reasonable distance
Explanation: these plants can be located near the load centre because of the negligible cost of transportation of fuel. but there should be a reasonable distance between the nuclear power plant and the nearest populated areas from point of view of safety against danger of radioactivity. it is highly undesirable to choose a site adjacent to chemical industries oil refineries pwd works hospitals and schools.

354. Operating cost of nuclear power plant is less than thermal power plant.
A. true
B. false

Answer: A true
Explanation: cost of fuel in nuclear power plant is taken as the capital cost. the the total operating cost involves wages and the salaries of operating and maintenance staff only, cost of disposal of waste etc.. the cost of transport and handling of coal for conventional thermal

355. PWR stands for
A. power
B. partially weathered rock
C. pressurized water reactor
D. packaging waste regulations

Answer: C pressurized water reactor
Explanation: pwr stands for pressurized water reactor. a pwr power plant consists of two loops in series. one is the coolant loop called primary loop and other is the water steam or working fluid loop. pressurized water reactor falls under the category of light water reactor.

356. What does the top of the pressurizer in pressurized water reactor consists of at primary system pressure?
A. steam
B. air
C. water
D. fluids

Answer: A steam
Explanation: the pressurizer is a pressure vessel with a heater at the bottom and water spray at the top. the top of the pressurizer is filled with steam at primary system pressure. if the primary loop pressure drops, the heater is energized to increase the steam content in the pressurizer and thus increases the pressure of primary cooling system.

357. Select the incorrect statement which supports PWR.
A. water is used as coolant
B. pwr is stable in operation
C. uses natural fuel
D. pwr has positive power demand coefficient

Answer: C uses natural fuel
Explanation: pwr uses enriched fuel making the reactor more compact in size. and due to high negative temperature coefficient, a pwr is stable. water is used as the coolant. it does have positive power demand coefficient and responds greatly to more power demand.

358. Select the incorrect statement about PWR.
A. high primary circuit pressure requires a strong pressure vessel
B. corrosion is less in pwr
C. during fuel charging in pwr, the reactor has to be shut down at least for a month
D. pwr results in uneven heating

Answer: B corrosion is less in pwr
Explanation: presence of high temperature and high pressure water, the corrosion is severe. this means use of stainless steel adds to further costing. when γ- radiations pass through the pressure vessel it results in uneven heating which induces thermal stresses on vessels.

359. LWR stands for
A. lower water reactor
B. line water reactor
C. liquefied water reactor
D. light water reactor

Answer: D light water reactor
Explanation: the light water reactor is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator – furthermore a solid fissile element is used as fuel. these are most common type of thermal-neutron reactors.

360. How many types of Boiling water reactor cycles are there?
A. 2
B. 3
C. 4
D. 5

Answer: B 3
Explanation: there are three different types of bwr cycles commonly used:

361. Which country invented CANDU heavy water reactor?
A. canada
B. germany
C. russia
D. bolivia

Answer: A canada
Explanation: the candu is a canadian pressurized heavy water reactor design used to generate electric power. heavy water nuclear reactors and light water nuclear reactors differ in how they create and manage the complex physics of nuclear fission or atom-splitting which produces the energy and heat to create steam to drive generators.

362. In which of the Following reactor is heavy hydrogen isotope H-2 is used as moderator?
A. boiling water reactor
B. pressurized water reactor
C. candu reactor
D. thermal reactor

Answer: C candu reactor
Explanation: heavy water composed of heavy hydrogen isotope h-2 is used as a moderator and coolant in some power and research reactors. these reactors use heavy water as a moderator and primary coolant and light water as secondary coolant.

363. CANDU stands for
A. canadian natural darmstadtium uranium
B. canadian natural deuterium uranium
C. canadian natural dubnium uranium
D. canadian natural dysprosium uranium

Answer: B canadian natural deuterium uranium
Explanation: the candu, for canada deuterium uranium, is a canadian pressurized heavy water reactor design used to generate electricity. the acronym refers to its deuterium oxide (heavy water) moderator and its use of (originally natural) uranium fuel.

364. Which reactor consists of both fertile and fissile material?
A. fast breeder reactor
B. pressurize water reactor
C. boiling water reactor
D. converter reactor

Answer: A fast breeder reactor
Explanation: if the reactor produces more fissionable material than it consumes, it is fast breeder reactor. the breeder fuel consists of both fertile and fissile material. the number of neutrons released is sufficient to propagate the fission reaction and to produce more fissionable material by conversion of fertile isotopes to fissile isotopes.

365. What is acronym of LMFBR?
A. liquid molecular fast boiling reactor
B. liquid metal fast breeder reactor
C. liquefied metal fast boiling reactor
D. liquid metal fast boiling reactor

Answer: B liquid metal fast breeder reactor
Explanation: lmfbr stands for liquid metal fast breeder reactor. the fuel consists of 80% by weight of uo2 by weight of puo2 in small diameter stainless steel clad tubes operating at temperature of 670oc – 700oc.

366. GCFBR stands for
A. gas conditioned fast breeder reactor
B. gas cooled fast breeder reactor
C. gas conditioned fast boiling reactor
D. gas cooled fast breeder reactor

Answer: B gas cooled fast breeder reactor
Explanation: the gcfbr stands for gas cooled fast breeder reactor; it is cooled by helium gas at 85bar. also helium doesn’t become radioactive under neutron bombardment and hence secondary coolant is not needed.

367. Using Helium gas in GCFBR has many advantages.
A. true
B. false

Answer: A true
Explanation: using helium as coolant posses less severe metallurgical and safety problems. heat transfer coefficient of helium is much superior than sodium with artificial roughening of fuel rod surfaces. low doubling time as compared to sodium cooled reactors.

368. Which reactor uses orthometaerhenyl and paratherphenyl as coolant and moderator?
A. liquid metal fast breeder reactor
B. gas cooled fast breeder reactor
C. organic substance cooled reactor
D. candu heavy water reactor

Answer: C organic substance cooled reactor
Explanation: organic substance cooled reactor uses enriched uranium as fuel and a mixture of orthometaterhenyl and paratherphenyl as coolant and moderator, and boron control rods, generating 11.4 mw capacities with an overall efficiency of 25%.

369. Nuclear plant is located near the area where cooling water is available.
A. true
B. false

Answer: A true
Explanation: some of the major factors to locate a nuclear station considered are, availability of cooling water, transportation facilities, distance from load centre, safety, radioactive waste, disposal facility and foundation requirement.

370. Which of the following may be used to measure the rate of nuclear disintegration?
A. geiger-muller counter
B. cold chamber
C. cyclotron
D. van de graph generator

Answer: A geiger-muller counter
Explanation: geiger-muller counter is used to measure the rate of nuclear disintegration.

371. The second underground nuclear test was conducted by India at
A. pokhran
B. narora
C. jaisalmer
D. kalpakkam

Answer: A pokhran
Explanation: pokhran was the place where

372. Which of the following may not need a moderator?
A. candu reactor
B. fast breeder reactor
C. homogeneous reactor
D. none of the mentioned

Answer: B fast breeder reactor
Explanation: fast breeder reactor may not need a moderator.

373. The mass number of an element is not changed, when it emits radiations.
A. α & γ
B. α, β, & γ
C. α & β
D. β & γ

Answer: D β & γ
Explanation: the mass number of an element is not changed when it emits β & γ radiations.

374. Which of the following is not a naturally occurring nuclear fuel?
A. uranium-238
B. thorium-233
C. plutonium-239
D. none of the mentioned

Answer: C plutonium-239
Explanation: plutonium-239 is an artificial nuclear fuel.

375. Which is the most commonly used molten metal for cooling of nuclear reactors?
A. zinc
B. sulphur
C. sodium
D. manganese

Answer: C sodium
Explanation: sodium is the most commonly used molten metal for cooling of nuclear reactors.

376. One amu is equivalent to?
A. 931 mev
B. 93.1 ev
C. 9.31 ev
D. 931 j

Answer: A 931 mev
Explanation: 91 mev constitutes one amu.

377. Fast breeder reactors do not
A. use molten sodium as coolant
B. use fast neutrons for fission
C. use th-232 as fissile fuel
D. convert fertile material to fissile material

Answer: C use th-232 as fissile fuel
Explanation: fast breeder reactors do not use thorium-232 as fuel.

378. A boiling water reactor is the one, in which the
A. pressurised water is pumped into the core.
B. coolant water, after being heated in the reactor core, generates steam in a boiler
C. fuel and the coolant are thoroughly mixed to form a homogeneous solution
D. coolant water is allowed to boil in the core of the reactor

Answer: D coolant water is allowed to boil in the core of the reactor
Explanation: a boiling water reactor is the one, in which the coolant water is allowed to boil in the core of the reactor.

379. Commercial power generation from fusion reactor is not yet possible, because
A. it is difficult to initiate fusion reaction
B. the fuel required (e.g. deuterium and tritium) is scarce
C. it is difficult to control fusion reaction
D. quantity of fuel required for initiating fusion reaction is prohibitively high

Answer: C it is difficult to control fusion reaction
Explanation: as fission reactions are hard to be controlled, the commercial power generation is not yet possible.

380. Thermal shield is used in high powered nuclear reactors to
A. absorb the fast neutrons
B. protect the walls of the reactor from radiation damage
C. slow down the secondary neutrons
D. protect the fuel element from coming in contact with the coolant

Answer: B protect the walls of the reactor from radiation damage
Explanation: thermal shield is used in high powered nuclear reactors to protect the walls of the reactor from radiation damage.

381. Which of the following energy has the greatest potential among all the sources of renewable energy?
A. solar energy
B. wind energy
C. thermal energy
D. hydro-electrical energy

Answer: A solar energy
Explanation: solar energy has the greatest potential of all the sources of renewable energy which comes to the earth from sun. this energy keeps the temperature of the earth above that in colder space, causes wind currents in the ocean and the atmosphere, causes water cycle and generates photosynthesis in plants.

382. What is the rate of solar energy reaching the earth surface?
A. 1016w
B. 865w
C. 2854w
D. 1912w

Answer: A 1016w
Explanation: the solar energy reaching the surface of the earth is about 1016w whereas the worldwide power demand is 1013w. that means solar energy gives us 1000 times more energy than our requirement.

383. What is total amount of solar energy received by earth and atmosphere?
A. 3.8 x 1024 j/year
B. 9.2 x 1024 j/year
C. 5.4 x 1024 j/year
D. 2.1 x 1024 j/year

Answer: A 3.8 x 1024 j/year
Explanation: even if we use 5% of this energy, it is more than 50 times our requirement. the total solar radiation absorbed by the earth and its atmosphere is

384. Which is most common source of energy from which electricity is produced?
A. hydroelectricity
B. wind energy
C. coal
D. solar energy

Answer: C coal
Explanation: coal is the most common source of energy that is being used since industrialization. modern steam boilers can burn coal in any of its form as a primary fuel. different ranks of coal available are peat, lignite, bituminous and anthracite.

385. In what form is solar energy is radiated from the sun?
A. ultraviolet radiation
B. infrared radiation
C. electromagnetic waves
D. transverse waves

Answer: C electromagnetic waves
Explanation: solar energy is radiated from the sun in the form of electromagnetic waves of shorter wavelength of 0.2 to 0.4 micrometers. out of all the solar energy radiations reaching the earth’s atmosphere, 8% is ultraviolet radiation, 40% is visible range light and 46% is by infrared radiation.

386. What does MHD stands for in the energy field?
A. magneto hydro dynamic
B. metal hydrogen detox
C. micro hybrid drive
D. metering head differential

Answer: A magneto hydro dynamic
Explanation: magneto hydro dynamic is a generator which is used for direct conversion of thermal energy into electrical energy. they work on faraday principle. when an electric conductor moves across a magnetic field, electric current is produced.

387. Solar radiation which reaches the surface without scattering or absorbed is called
A. beam radiation
B. infrared radiation
C. ultraviolet radiation
D. diffuse radiation

Answer: A beam radiation
Explanation: solar radiation that has not been absorbed or scattered and reaches the ground from the sun is called direct radiation or beam radiation. it is the radiation which produces a shadow when interrupted by an opaque object.

388. The scattered solar radiation is called
A. direct radiation
B. beam radiation
C. diffuse radiation
D. infrared radiation

Answer: C diffuse radiation
Explanation: diffuse radiation received from the sun after its direction has been changed by reflection and scattering by the atmosphere.

389. Solar radiation received at any point of earth is called
A. insolation
B. beam radiation
C. diffuse radiation
D. infrared rays

Answer: A insolation
Explanation: insolation is the total solar

390. Insolation is less
A. when the sun is low
B. when the sun right above head
C. at night
D. at sun rise

Answer: A when the sun is low
Explanation: the insolation at a given point or location on the earth’s surface depends among other factors, on the altitude of the sun in the sky. as a result of absorption and scattering, the insolation is less when the sun is low in the sky than when it is higher.

391. HHW stands for
A. high and low water
B. high level waste
C. heated low level water
D. high and low waste

Answer: B high level waste
Explanation: these are generated in reprocessing of spent fuel. they contain all fission products and contain of the transuranium elements not separated during reprocessing. such wastes are to be disposed of carefully.

392. What is unit of nuclear radiation?
A. reaumur
B. roentgen
C. rankine
D. pascal

Answer: B roentgen
Explanation: units of nuclear radiation is roentgen- amount of radiation which will on passing through pure air under standard condition produce 1 electrostatic unit of

393. Which type of fuel is removed from the reactor core after reaching end of core life service?
A. burnt fuel
B. spent fuel
C. engine oil
D. radioactive fuel

Answer: B spent fuel
Explanation: spent fuel is the unprocessed fuel that is removed from the reactor core after reaching end of core life service. it is removed and then stored for 3 to 4 months under water in the plant site to give time for the most intense radioactive isotopes to decay.

394. A solar cell is a
A. p-type semiconductor
B. n-type semiconductor
C. intrinsic semiconductor
D. p-n junction

Answer: D p-n junction
Explanation: a p-n junction which generated emf when solar radiation is incident on it is called a solar cell. the material used for fabrication of solar cell should have a band gap of around 1.5 ev.

395. Which of the following materials cannot be used as solar cells materials?
A. si
B. gaas
C. cds
D. pbs

Answer: D pbs
Explanation: if we use pbs as the solar cell material, then most of the solar radiation will be absorbed on the top-layer of the solar cell and will not reach in the depletion zone.

396. What is the difference between Photodiode and Solar cell?
A. no external bias in photodiode
B. no external bias in solar cell
C. larger surface area in photodiode
D. no difference

Answer: B no external bias in solar cell
Explanation: the solar cell does not need an external bias. it simply works on the incident solar radiation, which causes the creation of electron hole pairs.

397. During the collection of e-h pairs, holes are collected by
A. front contact
B. back contact
C. si-wafer
D. finger electrodes

Answer: B back contact
Explanation: as the electron-hole pairs move, the electrons are collected by the front contact and the holes reaching p-side are collected by the back contact.

398. What is the point where the graph touches the X-axis Indicate?
A. voltage breakdown
B. rms voltage
C. open circuit voltage
D. short circuit voltage

Answer: C open circuit voltage
Explanation: in the given figure, the point where the graph touches the x-axis shows the open circuit voltage while the point where it touches the y-axis shows the short circuit current.

399. The I-V characteristics of a solar cell are drawn in the fourth quadrant.
A. true
B. false

Answer: A true
Explanation: the i-v characteristics of a solar cell is drawn in the fourth quadrant of the coordinate axis because a solar cell does not draw current but supplies the same to the load.

400. What should be the band gap of the semiconductors to be used as solar cell materials?
A. 0.5 ev
B. 1 ev
C. 1.5 ev
D. 1.9 ev

Answer: C 1.5 ev
Explanation: semiconductors with band gap close to 1.5 ev are ideal materials for solar

401. Which of the following should not be the characteristic of the solar cell material?
A. high absorption
B. high conductivity
C. high energy band
D. high availability

Answer: C high energy band
Explanation: the energy band of the semiconductor should not be too high. it should be around 1.5 ev so that the incident solar radiation can cause the generation of e-h pairs.

402. Which of the following region is coated with a metal?
A. a
B. b
C. c
D. d

Answer: A a
Explanation: in the given figure, a is the back contact which is coated with a metal, b is the p-si wafer, c is the n-si wafer and d is the front contact which has metallized finger electrodes.

403. What does Heating and cooling of the atmosphere generates?
A. thermo line circulation
B. radiation currents
C. convection currents
D. conduction currents

Answer: C convection currents
Explanation: wind energy can be economically used for the generation of electrical energy. heating and cooling of the atmosphere generates convection currents. heating is caused by the absorption of solar energy on the earth surface.

404. How much is the energy available in the winds over the earth surface is estimated to be?
A. 2.9 x 120 mw
B. 1.6 x 107 mw
C. 1 mw
D. 5mw

Answer: B 1.6 x 107 mw
Explanation: the energy available in the winds over the earth surface is estimated to be

405. 6 X 107 MW which is almost the same as the present day energy consumption. Wind energy can be utilized to run wind mill which in turn, is used to drive the generators.
A. 20,000 mw
B. 12,000 mw
C. 140,000 mw
D. 5000 mw

Answer: A 20,000 mw
Explanation: india has a potential of 20,000 mw of wind power. wind power accounts nearly 9.87% of india’s total installed power generation capacity. generation of wind power in india mainly account from southern state of india.

406. Which country created wind mills?
A. egypt
B. mongolia
C. iran
D. japan

Answer: C iran
Explanation: the earliest known wind mills were in persia (iran). these early wind mills looked like large paddle wheels. centuries later, the people of holland improved the basic design of wind mill. holland is famous for its wind mills.

407. “During the day, the air above the land heats up more quickly than the air over water”.
A. true
B. false

Answer: A true
Explanation: during the day, the air above the land heats up more quickly than the air over water. the warm air over the land expands and raises, and the heavier, cooler air rushes in to take its place, creating winds.

408. What happens when the land near the earth’s equator is heated?
A. all the oceans gets heated up
B. small wind currents are formed
C. rise in tides
D. large atmospheric winds are created

Answer: D large atmospheric winds are created
Explanation: the large atmospheric winds that circle the earth are created because the land near the earth’s equator is heated more

409. What type of energy is wind energy?
A. renewable energy
B. non-renewable energy
C. conventional energy
D. commercial energy

Answer: A renewable energy
Explanation: wind is called a renewable energy source because the wind will blow as long as the shines. wind power, as an alternative to burning fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation, consumes no water, and uses little land.

410. What are used to turn wind energy into electrical energy?
A. turbine
B. generators
C. yaw motor
D. blades

Answer: A turbine
Explanation: wind turbine blades capture wind energy, a form of mechanical energy, and put it to work turning a drive shaft, gearbox, and generator to produce electrical energy. many factors affects wind turbine efficiency including turbine blade aerodynamics.

411. What is the diameter of wind turbine blades?
A. 320 feet
B. 220 feet
C. 80 feet
D. 500 feet

Answer: B 220 feet
Explanation: large utility-scale wind turbines can now generate more than a mw of electrical power each and deliver electricity directly in to the electric grid, these

412. At what range of speed is the electricity from the wind turbine is generated?
A. 100 – 125 mph
B. 450 – 650 mph
C. 250 – 450 mph
D. 30-35 mph

Answer: D 30-35 mph
Explanation: wind turbines are designed with cut-in wind speeds and cut-out speeds

413. When did the development of wind power in India began?
A. 1965
B. 1954
C. 1990
D. 1985

Answer: C 1990
Explanation: the development of wind power in india began in 1990s. presently india is the world’s fourth largest wind power generator. the indian energy sector has an installed capacity of 32.72 gw. today india is a major player in the global wind energy market.

414. A fuel cell is used to convert chemical energy into
A. mechanical energy
B. solar energy
C. electrical energy
D. potential energy

Answer: C electrical energy
Explanation: a fuel cell is used to convert chemical energy into electrical energy through a chemical reaction of positively charged hydrogen ions with oxygen or another oxidizing agent.

415. Select the incorrect statement from the following option.
A. fuel cells have high efficiency
B. the emission levels of fuel cells are far below the permissible limits
C. fuel cells are modular
D. the noise levels of fuel cells are high

Answer: D the noise levels of fuel cells are high
Explanation: the noise levels of fuel cells are low. they have high efficiency and are modular but the emission levels of fuel cells are far below the permissible limits.

416. and suitable catalyst are required to promote high rate of electrode processes.
A. lower temperature
B. higher temperature
C. moderate temperature
D. very low temperature

Answer: B higher temperature
Explanation: higher temperature and suitable catalyst are required to promote the high rate of electrode processes. the reaction at the anode produces electricity and water as by-products. the catalyst lowers the activation energy required, allowing the reaction to proceed more quickly or at a lower temperature.

417. Fuel cells are free from vibrations, heat transfer and thermal pollution.
A. true
B. false
C. topic 5.9 batteries – fuel cells – primary battery (dry cell) secondary battery (lead acid battery, lithium-ion- battery) fuel cells h2-o2 fuel cell.

Answer: A true
Explanation: fuel cells are free from vibrations, heat transfer and thermal pollution. the first commercial use of fuel cells came more than a century later in nasa space programs to generate power for satellites and space capsules.

418. Which of the following is not an example of a fuel cell?
A. hydrogen-oxygen cell
B. methyl-oxygen-alcohol cell
C. propane-oxygen cell
D. hexanone-oxygen cell

Answer: D hexanone-oxygen cell
Explanation: hydrogen-oxygen cell, methyl- oxygen-alcohol cell and propane-oxygen cell are some of the examples of fuel cells.

419. The electrolytic solution used in a hydrogen-oxygen fuel cell is
A. 75% koh solution
B. 25% koh solution
C. 75% naoh solution
D. 25% naoh solution

Answer: B 25% koh solution
Explanation: the electrolytic solution used

420. The standard emf of the hydrogen-oxygen fuel cell is
A. 1.23 v
B. 2.54 v
C. 3.96 v
D. 0.58 v

Answer: A 1.23 v
Explanation: the standard emf of the hydrogen-oxygen fuel cell is 1.23 v. this type of cell operates efficiently in the temperature range 343 k to 413 k.

421. The residual product discharged by the hydrogen-oxygen cell is
A. hydrogen peroxide
B. alcohol
C. water
D. potassium permanganate

Answer: C water
Explanation: the residual product discharged by the hydrogen-oxygen cell is water. it is formed by the oxidation reaction taking place at electrodes and combining the hydrogen and oxygen molecules.

422. Hydrogen-oxygen fuel cell can produce drinking water of potable quality.
A. true
B. false

Answer: A true
Explanation: hydrogen-oxygen fuel cell can produce drinking water of potable quality because the residual product discharged by the hydrogen-oxygen cell is water which is in its pure form.

423. Capacitor stores which type of energy?
A. kinetic energy
B. vibrational energy
C. potential energy
D. heat energy

Answer: C potential energy
Explanation: capacitor store charge in between the plates. this charge is stationary so we can say capacitor store potential energy.

424. Capacitor blocks after long time.
A. alternating current
B. direct current
C. both alternating and direct current
D. neither alternating nor direct current

Answer: B direct current
Explanation: capacitor blocks direct current at steady state and pass alternating current.

425. Why does capacitor block dc signal at steady state?
A. due to high frequency of dc signal
B. due to zero frequency of dc signal
C. capacitor doesnot pass any current at steady state
D. due to zero frequency of dc signal

Answer: D due to zero frequency of dc signal
Explanation: frequency of dc signal is zero. so, capacitive reactance xc=1/2πfc becomes infinite and capacitor behaves as open circuit for dc signal. hence, capacitor block dc signal.

426. 77*10-11 C. What is the voltage across the capacitor?
A. 1v
B. 2v
C. 3v
D. 4v

Answer: A 1v
Explanation: c=€0a/d

427. Which of the following is a passive device?
A. transistor
B. rectifier
C. capacitor
D. vaccuum tubes

Answer: C capacitor
Explanation: capacitor is a passive device as it consumes power rest all generate power so, they are active devices.

428. What is the value of capacitance of a capacitor which has a voltage of 4V and has 16C of charge?
A. 2f
B. 4f
C. 6f
D. 8f

Answer: B 4f
Explanation: q is directly proportional to v. the constant of proportionality in this case is c, that is, the capacitance. hence q=cv. from the relation, c=q/v= 16/4=4f.

429. For which medium capacitance is high?
A. air
B. mica
C. water
D. metal

Answer: D metal
Explanation: metals are assumed to have a high value of dielectric constant so they have high capacitance.

430. Alkaline hardness is due to the presence of bicarbonate, carbonate and hydroxides of the hardness-producing metal ions.
A. true
B. false

Answer: A true

431. The colour of dye metal complex and dye are
A. same
B. different
C. same in only some cases
D. cannot be known

Answer: B different

432. of zeolite.
A. 10,000
B. 20,000-30,000
C. 35,000-40,000
D. 40,000-50,000

Answer: C 35,000-40,000

433. m2
A. 112
B. 115
C. 117
D. 120

Answer: A 112

434. m3/h. Feed flow : 635 m3/h.
A. 80%
B. 85%
C. 90%
D. 75%

Answer: B 85%

435. 5 and C = 0.04.
A. 0.050
B. 0.030
C. 0.040
D. 0.060

Answer: C 0.040

436. If a reaction is nth order the half-life period of the initial concentration of the reactants.
A. is independent
B. varies inversely as (n-1)th power
C. varies inversely as nth power
D. varies directly as (n-1)th power

Answer: B varies inversely as (n-1)th power

437. The elementary processes with molecularity greater than are not known.
A. 1
B. 2
C. 3
D. 0

Answer: C 3

438. SO2 + O2 ⟶ 2SO3
A. chlorine
B. nitrous oxide
C. sulphur di oxide
D. potassium chloride

Answer: B nitrous oxide

439. + 3H2 ⟶ 2NH3
A. zinc
B. chlorine
C. platinum
D. water

Answer: C platinum

440. O2 ⟶ 2H2O + O2
A. chlorine
B. bromine
C. platinum
D. noble solutions

Answer: C platinum

441. + O2 ⟶ 2SO3
A. platinum
B. bromine
C. magnesium
D. silver

Answer: A platinum

442. C=12
A. 1
B. 0
C. 2
D. 10

Answer: D 10

443. = K +α′ S]
A. repressor
B. inhibitor
C. modulator
D. regulator

Answer: B inhibitor

444. What is Gibbs phase rule for general system?
A. p = c – 1 – f
B. p = c + 1 – f
C. p + f = c – 2
D. p + f = c + 2

Answer: D p + f = c + 2

445. atm Temperature: 1oC
A. 0
B. 2
C. 1
D. 3

Answer: C 1

446. Which of the following compound is considered for calculating the octane number?
A. n-heptane
B. n-hexane
C. iso-octane
D. iso-butane

Answer: C iso-octane

447. For best results of efficient combustion, high speed diesel engines need an approximate cetane number of
A. 100
B. 10
C. 50
D. 5

Answer: C 50

448. The most popular firing order in case of four cylinder in-line I.C. engine is
A. 1-2-3-4
B. 1-3-2-4
C. 1-4-2-3
D. 1-3-4-2

Answer: D 1-3-4-2

449. The compression ratio of motor cars is
A. 5
B. 7
C. 10
D. 13

Answer: B 7

450. The efficiency of I.C. engines normally is of the order of
A. 15-20%
B. 20-25%
C. 25-30%
D. 30-35%

Answer: D 30-35%

451. The firing order of a six stroke I.C. engine is
A. 1-3-6-5-2-4
B. 1-4-2-5-6-3
C. 1-6-2-5-4-3
D. 1-5-3-4-2-6

Answer: D 1-5-3-4-2-6

452. Sulphur content in diesel engine oil should not be more than
A. 10%
B. 5%
C. 1%
D. 0.1%

Answer: C 1%

453. Which of the following is a major advantage of gaseous fuel over liquid and solid fuel?
A. gaseous coal does not form ash
B. gaseous coal can be manufactured at a central place
C. oxidising and reducing atmospheres can be easily maintained
D. they are economic than solid and liquid fuels

Answer: A gaseous coal does not form ash

454. Disadvantage of hydrogen as a fuel in IC engine is
A. storage is safe
B. low nox
C. detonating tendency
D. easy handling

Answer: C detonating tendency

455. Major disadvantage of LPG as fuel in automobiles is
A. reduction in life of engine
B. less power compared to gasoline
C. all of the mentioned
D. none of the mentioned

Answer: C all of the mentioned

456. Hydrogen gas has self- ignition temperature.
A. very low
B. very high
C. no
D. none of the mentioned

Answer: B very high

457. The energy content of air hydrogen mixture is than liquid hydrocarbon fuels.
A. lower
B. higher
C. negligible
D. none of the mentioned

Answer: A lower

458. CNG has high auto-ignition temperature of
A. 813k
B. 993k
C. 1163k
D. 1273k

Answer: A 813k

459. The rating of a diesel engine, with increase in air inlet temperature, will
A. increase linearly
B. decrease linearly
C. increase parabolically
D. decrease parabolically

Answer: B decrease linearly

460. The knock in diesel engine occurs due to
A. instantaneous and rapid burning of the first part of the charge
B. instantaneous auto ignition of last part of charge
C. reduction of delay period
D. none of the mentioned

Answer: A instantaneous and rapid burning of the first part of the charge

461. Volatility of diesel fuel is
A. maximum temperature to which oil is heated in order to give off inflammable vapour in sufficient quantity to ignite momentarily when bought in contact with a flame
B. it catches fire without external aid
C. indicated by 90% distillation temperature
D. none of the mentioned

Answer: C indicated by 90% distillation temperature

462. Violent sound pulsations within the cylinder of an I.C. engine are caused due to
A. heavy turbulence
B. improved scavenging
C. detonation
D. pre-ignition

Answer: C detonation

463. The delay period in petrol engine is of the order of
A. 0.001 sec
B. 0.002 sec
C. 0.01 sec
D. 0.1 sec

Answer: B 0.002 sec

464. In order to prevent knock in the S.I. engines, the charge away from the spark plug should have
A. low temperature
B. low density
C. rich mixture
D. all of the mentioned

Answer: D all of the mentioned

465. To reduce the possibility of knock in C.I. engines, the first elements of fuel and air should have
A. high temperature
B. high density
C. short delay
D. all of the mentioned

Answer: D all of the mentioned

466. The detonation tendency in petrol engines for specified conditions of fuel rating, compression ratio, speed etc, can be controlled by having
A. smaller cylinder bore
B. bigger cylinder bore
C. medium cylinder bore
D. none of the mentioned

Answer: A smaller cylinder bore

467. A fuel will detonate less if it has
A. higher self ignition temperature
B. lower self ignition temperature
C. proper self ignition temperature
D. none of the mentioned

Answer: A higher self ignition temperature

468. Which of the following compound other than CO2, CO an O2 can be determined by the flue gas analysis?
A. c2h6
B. c6h6
C. c6h11o22
D. ethylene

Answer: A c2h6

469. Why neutrons with lower energy should be capable of causing fission?
A. for faster reaction process
B. for sustained reaction process
C. for safety purpose
D. in order to not waste the nuclear fuel

Answer: B for sustained reaction process

470. In economics of nuclear power plant taxes and insurance charges are taken as
A. operating cost
B. maintenance cost
C. capital cost
D. fixed cost

Answer: D fixed cost

471. O + CO2 →
A. ch2o + o2
B. co2 + o2
C. h + co2 + o2
D. ch2o + h2o + o2

Answer: A ch2o + o2

472. The principle of a solar cell is same as the photodiode.
A. true
B. false

Answer: A true

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