Automobile Engineering Multiple Choice Questions on “Heat Engines”.
1. A heat engine converts heat energy from fuel combustion or any other source into which type of work?
a) Electrical work
b) Mechanical work
c) Pressure work
d) None of the mentioned
Answer: b
Clarification: A heat engine gives mechanical work as output. In a heat engine, input is given in the form of heat and this heat is converted into mechanical work. The remaining heat which is not converted into work is exhausted.
2. A steam engine comes under the category of ________
a) External combustion engines
b) Internal combustion engines
c) All of the mentioned
d) None of the mentioned
Answer: a
Clarification: A steam engine is an External combustion engine. Steam engine is a type of heat engine in which heat is used as an input and this heat is converted into mechanical work. Steam pushes the piston and reciprocating motion of the piston is converted into rotary motion.
3. Which of these is a power absorbing heat engine?
a) Steam engine
b) Petrol engine
c) Air compressor
d) None of the mentioned
Answer: c
Clarification: An air compressor is a power absorbing heat engine.
4. Which of these is a type of reciprocating steam engine?
a) Simple
b) Compound
c) Uniflow
d) All of the mentioned
Answer: d
Clarification: Simple, compound and uniflow are types of reciprocating steam engine.
5. A gas undergoes step 2 in Carnot cycle. Which of these processes describes the 2nd step?
a) Isentropic expansion
b) Isentropic compression
c) Isothermal expansion
d) Isothermal compression
Answer: a
Clarification: The 2nd process in carnot cycle is isentropic expansion.
6. A gas undergoes step 4 in Carnot cycle. Which of these processes describes the 2nd step?
a) Isentropic expansion
b) Isentropic compression
c) Isothermal expansion
d) Isothermal compression
Answer: b
Clarification: The 4th process in carnot cycle is isentropic compression.
7. A gas undergoes isothermal compression in Carnot cycle. Which step does it undergo?
a) 1st
b) 2nd
c) 3rd
d) 4th
Answer: c
Clarification: Isothermal compression is the 3rd step in Carnot cycle.
8. Thermal power plants operate on which of these cycles?
a) Otto cycle
b) Rankine cycle
c) Carnot cycle
d) Stirling cycle
Answer: b
Clarification: Thermal power plants operate on Rankine cycle.
9. The efficiency of a combined cycle gas turbine(steam cooled) can range as high as ________
a) 20%
b) 30%
c) 40%
d) 60%
Answer: d
Clarification: A steam cooled combined cycle gas turbine can have efficiency as high as 60%.
10. One ‘ton of refrigeration’ equals how much Btu/hr.
a) 14,500 Btu/hr
b) 12,000 Btu/hr
c) 13,000 Btu/hr
d) 15,000 Btu/hr
Answer: b
Clarification: One “ton of refrigeration (TR or TOR)” is equivalent to 12,000 Btu/hr or 3.5 kW. It is the unit of power which is used to describe the heat extraction capacity of a refrigeration or air conditioning equipment.
11. Working pressure of a boiler does not depend upon
A. Factor of safety
B. Tensile strength of shell
C. Thickness of shell
D. Efficiency of joint
E. Type of fuel being fired
Answer: E.Type of fuel being fired
12. Oil rings are slotted to
A. Remove oil from cylinder
B. Minimise friction
C. Reduce the bulk
D. Better lubrication of cylinder walls
E. Provide an escape for the oil that the slot edges cut from the cylinder wall
Answer: E.Provide an escape for the oil that the slot edges cut from the cylinder wall
13. A gas turbine cycle operates through pressures ratio of 5. Air enters the compressor at atmospheric pressure and 25?C and entry to the turbine is at 800?C. The thermal efficiency of the plant has been found to be 37%. Now, if compressor and turbine efficiencies of 80% are taken into account, the value, of thermal efficiency will be
A. 37%
B. 40%
C. 38.50%
D. 17.75%
E. 45%
Answer: D.17.75%
14. The chemical usually added for increasing the knock resistance of a petrol engine is
A. Tetra-ethy lead
B. n-heptane
C. Pyro gallic acid
D. Methyl alcohol
E. Benzol
Answer: A.Tetra-ethy lead
15. Pure cetane
A. Has cetane number of 0
B. Promotes detonation
C. Is a straight chain paraffin
D. Has cetane number of 100
E. Is a blue coloured liquid
Answer: C.Is a straight chain paraffin
16. In aircraft using gas turbine the cycle used is
A. Reheating
B. Regeneration
C. Reheating with regeneration
D. Simple
E. Multi-stage expansion with reheating and regeneration
Answer: D.Simple
17. Which of the following automobile is relatively free from pollution problems
A. Diesel engine powered
B. Wankel engine powered
C. Batterly powered
D. Gas turbine powered
E. Petrol engine powered
Answer: C.Batterly powered
18. During idling a petrol engine requires
A. Rich mixture
B. None of above
C. Chemically correct mixture
D. Variable mixture
E. Lean mixture
Answer: A.Rich mixture
19. A diesel engine is to be redesigned to improve the overload capacity. The design feature which will be influenced is
A. Size of fuel injection equipment
B. Lubrication
C. Air capacity of cylinder
D. Cooling water velocity
E. All of the above
Answer: E.All of the above
20. Which of the following pollutants result from automobile exhaust?
A. Carbon monoxide
B. Nitrous oxide
C. Hydro carbons
D. Sulphur dioxide
E. All of the above
Answer: E.All of the above
21. Which is incorrect?
A. Compression ratio = initial volume + final volume
B. Final pressure = Initial pressure x compression ratio
C. Initial pressure = final pressure + compression ratio
D. Initial volume = compression ratio x final volume
E. None of the above
Answer: E.None of the above
22. Coking is
A. Formation of lumps or masses of coke in boiler furnaces at high temperatures
B. Heating of coal in absence of air driving carbon and leaving behind the residue of carbon
C. Burning of coal in a furnace
D. Producing lumps of coal from fine powders with the help of a binder
E. None of the above
Answer: B.Heating of coal in absence of air driving carbon and leaving behind the residue of carbon
23. In a diesel engine the inlet pressure is more than the atmospheric pressure. Therefore; it can be concluded that
A. The engine is high speed type
B. The engine is air cooled
C. The engine is water cooled
D. The engine is slow speed type
E. The engine is supercharged
Answer: E.The engine is supercharged
24. In a impulse turbine while steam flows through the moving blades
A. Velocity increases
B. Velocity reduces
C. Both velocity as well as pressure increase
D. Velocity reduces while pressure increases
E. Pressure reduces
Answer: B.Velocity reduces
25. A hydrograph is a plot of discharge through a river versus
A. Time
B. Velocity of water
C. Rate of flow of water
D. None of the above
E. None of the above
Answer: A.Time
26. A gas used in gas engine trial was tested in a Boys Calorimeter. The pressure of gas supply was 7 cm of water column. If the barometric pressure is 760 mm of mercury, the absolute pressure of the gas would be
A. 0.007 kg/sq-cm
B. 0.14 kg/sq-cm
C. 1.04 kg/sq-cm
D. 1.14 kg/sq-cm
E. None of the above
Answer: C.1.04 kg/sq-cm
27. A cross-head has
A. Reciprocating motion
B. Rotory motion
C. Oscillating motion
D. (A) and (B) only
E. (A) and (C) only
Answer: A.Reciprocating motion
28. An average percentage of Carbon and Hydrogen in Petrol may be roughly given as
A. 70% C, 70% H2
B. 15% C, 85% H2
C. 50% C, 50% H2
D. 85% C, 150% H2
E. 60% C, 40% H2
Answer: D.85% C, 150% H2
29. The overload capacity of diesel engine is usually around
A. 50%
B. Carbon dioxide
C. 1%
D. 25%
E. 10%
Answer: E.10%
30. A gas turbine plant operates between 1 ata and 9 ata with minimum and maximum cycle temperature of 25?C and 1000?C. A two stage compressor is provided with perfect intercooling and work is equally divided between the two stages. The intermediate pressure will be
A. 5.5 ata
B. 3 ata
C. 4 ata
D. 7.5 ata
E. 5 ata
Answer: B.3 ata
31. In cse the exhaust silencer of a petrol engine is partly choked, it is likely to result in
A. Increased compression ratio
B. Increased fuel consumption
C. Reduced fuel consumption
D. Reduced compression ratio
E. None of the above
Answer: B.Increased fuel consumption
32. Which of the following engine uses two fuel simultaneously?
A. Multi-fuel engine
B. Duel fuel engine
C. Wankle engine
D. Free piston gas generator
E. All of the above
Answer: B.Duel fuel engine
33. Which of the following constituent of air has the least proportion?
A. Carbon monoxide
B. Xenon
C. Argon
D. Helium
E. Neon
Answer: B.Xenon
34. Which of the following is a false statement. A multicylinder diesel engine is missing on one or more cylinders. The cause may be
A. Valve sticky
B. Insufficient fuel supply to cylinders
C. Compression poor
D. Air cleaner plugged
E. Valves leaky
Answer: D.Air cleaner plugged
35. If a steam injector lifts the water but fails to force it into the boiler, the trouble may not be due to
A. Combining tube clogged
B. Insufficient steam pressure
C. Sry steam
D. Leake in water pipe
E. Any of the above
Answer: C.Sry steam
36. Which one of the following symptoms will not show that combustion is becessary complete.
A. Presence of free carbon in exhaust
B. Presence of carbon monoxide in exhaust
C. Presence of oxygen in exhaust
D. Presence of nitrogen in exhaust
E. All of the above
Answer: D.Presence of nitrogen in exhaust
37. Presence of impurities in ice
A. Does not have any effect
B. Lowers melting point
C. Makes it heavier than water
D. Raises melting point
E. Depends on other factors
Answer: B.Lowers melting point
38. Piston rod is provided in
A. Slow speed steam engines
B. Double acting steam engines
C. High speed steam engines
D. Non-condensing steam engines
E. Condensing steam engines
Answer: B.Double acting steam engines
39. The pressure of steam generated in a boiler as recorded by the Bourdon pressure gauge was 2.2 kg/sq-cm. If the barometer reads 774 mm of mercury the absolute pressure of steam would be
A. 0.2 kg/sq-cm
B. 9.774 kg/sq-cm
C. 1.025 kg/sq-cm
D. 77.4 mm of Hg
E. 3.2526 kg/sq-cm
Answer: E.3.2526 kg/sq-cm
40. Which statement is false in case of SI engines
A. Accetylene has least tendency to knocking
B. Adding methyl groups to the side of the carbon chain increases the knocking tendency
C. Unsaturated aliphatic hydrocarbons show less knocking tendency
D. Increasing the length of the carbon chain increases the knocking tendency
E. Centralising the carbon atoms decreases the knocking tendency
Answer: A.Accetylene has least tendency to knocking
41. In a petrol engine as the speed increases
A. The spark intensity has to be increased
B. The spark intensity has to be reduced
C. The spark has to be advanced
D. The spark has to be retarded
E. None of the above
Answer: D.The spark has to be retarded
42. In thermodynamics, forced processes are those
A. Where a difference is observed in any microscopic property of the system between different times of states
B. Where a difference is observed in any microscopic property of the system between different times or states
C. Which occur in the direction of an intensive property or driving force contained within the system
D. Which require an agency outside the system to force the process
E. None of the above
Answer: D.Which require an agency outside the system to force the process
43. The steam in a boiler drum is always
A. Dry and saturated
B. Wet or dry and saturated
C. Dry
D. Wet
E. Superheated
Answer: D.Wet
44. Which of the following is false statement? The cause of slow cranking of a gas engine during starting may be
A. Partially discharged battery
B. Under capacity battery
C. High air temperature
D. Heavy engine oil
E. Faulty starting motor
Answer: C.High air temperature
45. The work done on a compressor will be least when air is taken from
A. As and where available
B. Source of low temperature air
C. A source at 0?C
D. Atmosphere
E. Source of high temperature air
Answer: B.Source of low temperature air
46. A coal contains 3.5% sulphur by weight, as fired, and all the sulphur may be assumed to go to formation of sulphur dioxide. How many tonnes of SO2 are produced per day of the firing rate is 35 tonnes per hour
A. 54.8
B. 60.8
C. 48.8
D. 58.8
E. 100
Answer: D.58.8
47. The total length of 40 mid-ordinates on a simple steam engine indicator diagram is 17 cm. The pressure scale is 0.6 kg/sq-cm. The mean effective pressure would be
A. 1.0 kg/sq-cm
B. 1.7 kg/sq-cm
C. 1.0 kg/sq-cm
D. 10.2 kg/sq-cm
E. None of the above
Answer: C.1.0 kg/sq-cm
48. Free air is air at
A. 1 kg/cm2 and 20?C
B. 1 kg/cm2 and atmospheric temperature
C. 1 kg/cm2 and 27?C
D. 1 kg/cm2 and 0?C
E. Atmospheric conditions at any specific location
Answer: E.Atmospheric conditions at any specific location
49. De-Laval turbine is mostly used
A. For small powers at high speeds
B. For small powers at low speeds
C. For high powers at low speeds
D. For high powers at high speeds
E. None of the above
Answer: A.For small powers at high speeds
50. Air fuel ratio for a jet engine is of the order of
A. 15 ; 1
B. 20 ; 1
C. 60 ; 1
D. 400 ; 1
E. 10 ; 1
Answer: C.60 ; 1
51. A petrol engine as compared to diesel engine (both running at full load) is
A. More efficient
B. Less efficient
C. Equally efficient
D. Depend on other factors
E. None of the above
Answer: B.Less efficient
52. Which one of the following assumptions is not involved while deriving relation for air standard efficiency of Otto cycle?
A. The engine operates at mederate rpm
B. There is always thermal and chemical equilibrium
C. Expansion and compression are adiabatic
D. There is no chemical reaction inside the engine clinder
E. The working fluid is air for which the specific heats are constant
Answer: A.The engine operates at mederate rpm
53. Which of the following needs constant cleaning in a diesel engine?
A. Air only
B. Fuel only
C. Air, fuel and lubricating oil
D. Lubricating oil only
E. Air and fuel only
Answer: C.Air, fuel and lubricating oil
54. Bagasse is
A. Fibrous portion of sugarcane left after extracting the juice
B. A variety of coal
C. A fuel consisting of wood etc
D. Same as biogas
E. A kind of rice straw
Answer: A.Fibrous portion of sugarcane left after extracting the juice
55. During regenerative feed heating
A. Part of the steam is generated in turbine
B. Condenser is supplied with dry and staturated steam
C. Part of the steam is bled from turbine for feed water heating
D. High pressure steam is used to heat low pressure steam coming out of the turbine after expansion
E. None of the above
Answer: C.Part of the steam is bled from turbine for feed water heating
56. A jet engine has
A. Propeller in front
B. Propeller in back
C. No propeller
D. Propeller on the top
E. None of the above
Answer: C.No propeller
57. Anti-knock for compression ignition engines is
A. Amyl nitrate
B. Aromatics
C. Hexadecane
D. Tetra ethyl lead
E. Trimethyl pentane
Answer: C.Hexadecane
58. Which statement is incorrect?
A. LH.P of engines can be determined by more test
B. Morse test can be conducted only on multicylinder engines
C. Morse test can be conducted on petrol engines
D. Morse test can be conducted on CFR engine.
E. Morse test can also be conducted on diesel engines
Answer: D.Morse test can be conducted on CFR engine.
59. Advantage of a diesel engine over petrol engine is
A. Low fuel consumption at full load as well as part load
B. Smooth operation at all speeds
C. Low compression ratio
D. No detonation problems
E. All of the above
Answer: A.Low fuel consumption at full load as well as part load
60. Forced circulation of water does not take place in which of the following boiler?
A. Benson boiler
B. La Mont boiler
C. Babcock and Wilcox boiler
D. Lancashire boiler
E. Velox boiler
Answer: D.Lancashire boiler
61. In multistage compression, perfect intercooling means
A. Temperature of air at inlet to subsequent stages is equal to initial temperature
B. Temperature of air at inlet to subsequent stages is less than initial temperature
C. Temperature of air at inlet to subsequent stages should be zero
D. Temperature of inlet to subsequent stages should be equal to the final temperature
E. None of the above
Answer: A.Temperature of air at inlet to subsequent stages is equal to initial temperature
62. The battery used in vespa scooter is
A. No battery is used in the scooters
B. Dry-cell type
C. Lead acid type
D. Nickel-iron type
E. Nickel cadmium type
Answer: A.No battery is used in the scooters
63. Which variety of coal has low calorific value?
A. Steam coal
B. Bituminous coal
C. Lignite
D. Anthracite
E. None of the above
Answer: C.Lignite
64. Stoichiometric ratio is
A. Chemically correct air-fuel ratio by volume
B. Chemically correct air-fuel ratio by weight
C. Theoretical mixture of air for complete combustion
D. Actual ratio of air to fuel for maximum efficiency
E. None of the above
Answer: B.Chemically correct air-fuel ratio by weight
65. Hot spots are
A. Defects in S.I.engines
B. Hottest point within engine cylinder
C. Do not exist in engines
D. The spots where heavier fractions of fuel are vaporised
E. The hottest spots in engines
Answer: D.The spots where heavier fractions of fuel are vaporised
66. Air required for complete combustion of 1 kg of carbon is 11.6 kg. If a fuel contains 88.6% Carbon and 11.4% Hydrogen, the air requirement will
A. Will decrease
B. 12 kg
D. Will increase
E. Remain unaltered
Answer: D.Will increase
67. Volumetric efficiency of a well designed engine may be in the range
A. 40 to 50 percent
B. 50 to 75 percent
C. 75 to 90 percent
D. Below 40 percent
E. Below 20 percent
Answer: C.75 to 90 percent
68. If the boiler chimney emission consists of dense white smoke, then it can be concluded that
A. Coal contains high percentage of sulphur
B. Insufficient air has been supplied for combustion
C. Chemically correct air has been supplied for combustion
D. Excess air has been supplied for combustion
E. Coal contains high percentage of ash
Answer: B.Insufficient air has been supplied for combustion
69. Compression ratio in case of gas engines waries in the range
A. 10 to 15
B. 5 to 10
C. 24 to 30
D. 20 to 24
E. 15 to 20
Answer: B.5 to 10
70. A back pressure generally operates on pressures in the range
A. 150 – 200 kg/cm2
B. 15 – 40 kg/cm2
C. 100 – 150 kg/cm2
D. 50 – 100 kg/cm2
E. 200 – 350 kg/cm2
Answer: B.15 – 40 kg/cm2
71. In automobiles as the speed of vehicle increases the back pressure
A. Increases
B. Reduces
C. Remains unaffected
D. Depends on other factors
E. None of the above
Answer: D.Depends on other factors
72. A mechanical indicator is used to determine
A. Pumping horse power
B. Indicated horse power
C. IHP – BHP
D. Friction horse power
E. Brake horse power
Answer: B.Indicated horse power
73. During adiabatic compression
A. No heat leaves or enters the system
B. Maximum work is done
C. Specific heat remains constant
D. Temperature remains constant
E. None of the above
Answer: A.No heat leaves or enters the system
74. Safety valve generally used on high pressure boiler is
A. Dead weight type
B. Lever type
C. Combination lever and spring type
D. Spring type
E. None of the above
Answer: D.Spring type
75. Which of the following engine indicator has least inertia effects?
A. Mechanical indicator
B. Farnborough indicator
C. CRO engine indicator
D. All of the above
E. Carbon dioxide
Answer: C.CRO engine indicator
76. Calorific value of methane gas can be determined by
A. Bomb calorimeter
B. Bunsen’s apparatus
C. Orsat’s apparatus
D. None of the above
E. At constant temperature
Answer: D.None of the above
77. Which one of the following factors will not assist in improving thermal efficiency of a compression ignition engine?
A. Fine atomisation and even distribution of fuel
B. Minimum heat loss during combustion
C. Clear exhaust
D. High surface to volume ratio
E. Any of the above
Answer: D.High surface to volume ratio
78. A diesel power plant is best suited as
A. Base load plant
B. Stand by plant
C. Peak load plant
D. General purpose plant
E. None of the above
Answer: B.Stand by plant
79. Excessive moisture in steam in a steam turbine is likely to result in
A. Erosion of turbine blades
B. Excess work done by rotor due to momentum of water particles
C. Overheating of turbine blaces
D. Reduced load on condenser
E. Reduced size of steam turbine
Answer: A.Erosion of turbine blades
80. According to Boyle’s law
A. At constant pressure the temperature of a gas varies inversely as its volume
B. At constant pressure the absolute temperature of a gas varies inversely as its volume
C. At constant temperature, the pressure of a gas varies inversely as its volume
D. At constant temperature, the absolute pressure of a gas varies inversely as its volume
E. None of the above
Answer: D.At constant temperature, the absolute pressure of a gas varies inversely as its volume
81. An optical pyrometer works on the principle of
A. Expansion of fluids
B. Mono-chromatic radiation
C. Thermo-electric effect
D. Total radiation
E. Change of electrical resistance
Answer: B.Mono-chromatic radiation
82. Air fuel ratio for a jet engine is of the order of
A. 15 ; 1
B. 20 ; 1
C. 400 ; 1
D. 60 ; 1
E. 10 ; 1
Answer: D.60 ; 1
83. The top ring nearest to the piston crown is known as
A. Oil ring
B. Scrapper ring
C. Compression ring
D. Groove ring
E. Any of the above
Answer: C.Compression ring
84. The vapour pressure is related to the enthalpy of vaporization in
A. Maxwell’s equation
B. Henry’s law
C. Dalton’s law
D. Clausius Clapeyron equation
E. Raoult’s law
Answer: D.Clausius Clapeyron equation
85. Flash point of a liquids is the temperature at which
A. The fuel ignites with clearly visible flash
B. Fuel vaporises at the prescribed rate
C. The fuel emits vapours at a rate which produces an inflammable mixture with air
D. The fuel ignites without a park
E. The fuel spontaneously ignites
Answer: C.The fuel emits vapours at a rate which produces an inflammable mixture with air
86. According to kinetic theory of heat
A. At absolute zero there is absolutely no vibration of molecules
B. At low temperatures all bodies are in solid state
C. 25 to 30
D. Temperature should rise during boiling
E. Temperature should fall during freezing
Answer: A.At absolute zero there is absolutely no vibration of molecules
87. Regenerative feed heating of steam turbines is done primarily to
A. Improve thermal efficiency of the condenser
B. Increase the expansion range for steam in the turbine
C. Improve overall efficiency of the plant
D. Reduce pressure of steam in exhaust
E. Reduce boiler losses in the gases
Answer: C.Improve overall efficiency of the plant
88. Ricardo’s theory is associated with
A. Steam turbines
B. Wankel engines
C. Internal combustion engines
D. Closed cycle gas turbines
E. Engine vibrations
Answer: C.Internal combustion engines
89. A ‘blue’ flame is
A. Non-radiant flame
B. Radiant flame
C. Super high temperature flame
D. Ordinary flame in oil burners
E. None of the above
Answer: A.Non-radiant flame
90. The thermal efficiency of a dual cycle engine with fixed compression ratio and fixed quantity of het and with increase in pressure ratio, will
A. Increase
B. Decrease
C. Not change
D. Depends on another factors
E. None of the above
Answer: A.Increase
91. Turbidity in boiler feed water causes
A. Sludge
B. Embrittlement
C. Corrosion
D. Scale
E. None of the above
Answer: A.Sludge
92. A mixture containing 60% cetane and 40% Iso-octane will have
A. Cetane number 60
B. Cetane number 40
C. Octane number 60
D. Octane number 40
E. None of the above
Answer: E.None of the above
93. A vacuum of 712 mm was obtained with the barometer reading 753 mm of mercury. The corrected vacuum to a standard barometer of 760 would be
A. 719 mm Hg
B. 753 mm Hg
C. 706 mm Hg
D. 760 mm Hg
E. 712 mm Hg
Answer: A.719 mm Hg
94. Flash point for diesel fuel oil should be
A. Minimum 49?C
B. Maximum 49?C
C. Maximum 100?C
D. Maximum 200?C
E. None of the above
Answer: A.Minimum 49?C
95. The knocking tendency in a compression ignition engine for a given fuel will
A. Enhance by reducing compression ratio
B. Enhance by increasing compression ratio
C. Depend on other factors
D. Increase to certain limits and then no change
E. None of the above
Answer: A.Enhance by reducing compression ratio
96. A steam turbine in which a part of the steam turbine after partial expansion is used for process heating and the remaining steam is further expanded for power generation, is known as
A. Impulse turbine
B. Regenerative turbine
C. Back pressure turbine
D. Pass out turbine
E. 50% reaction turbine
Answer: D.Pass out turbine
97. A De-Laval turbine is
A. Multiple stage reaction turbine
B. Single rotor impulse turbine
C. Multiple rotor reaction turbine
D. Velocity compounded impulse turbine
E. Single rotor reaction turbine
Answer: B.Single rotor impulse turbine
98. In a cut off covered steam engine
A. Admission pressore remains constant while cut off is varied
B. Admission pressure is reduced while cut off remains unaltered
C. Admission pressure and cut off both are varied
D. Neither admission pressure nor cut off is varied
E. Admission pressure is increased while cut off remains unaltered
Answer: A.Admission pressore remains constant while cut off is varied
99. Which one of the following is a safety device on a compressor?
A. Intercooler relief valve
B. Over pressure shut down
C. Strainer
D. Over speed shut down
E. Relief valve
Answer: E.Relief valve
100. Naphtha is used as
A. Lubricant for turbines
B. Lubricant for slow speed engines
C. Fuel for marine engines
D. Fuel for furnaces
E. Fuel for aero engines
Answer: D.Fuel for furnaces
101. The maximum horse power of Fiat engine is around
A. 11
B. 15
C. 40 to 50
D. 25 to 30
E. 60 to 80
Answer: C.40 to 50
102. An air fuel ratio 8 will have
A. Chemically correct air
B. Excess fuel
C. Excess air
D. Any of above
E. None of above
Answer: B.Excess fuel
103. Consumption of diesel in a diesel engine per BHP per hour is in the range
A. 185-210 gm
B. 215-300 gm
C. 500-800 gm
D. 100-150 gm
E. 150-180 gm
Answer: A.185-210 gm
104. When a receiver is provided in a compound engine, it can be concluded that
A. The engine is non-condensing type
B. The engine is condensing type
C. The cranks are at 90? to each other
D. The cranks are at 180? to each other
E. None of the above
Answer: C.The cranks are at 90? to each other
105. The emission of oxides of nitrogen in automobile exhaust will be least when the vehicle is
A. Decelerating
B. Accelerating
C. Cruising at low speeds
D. Idling
E. Cruising at high speeds
Answer: D.Idling
106. A gas turbine works on
A. Brayton cycle
B. Joule cycle
C. Carnot cycle
D. Rankine cycle
E. Erricson cycle
Answer: A.Brayton cycle
107. Isolate the factor on which bursting pressure of boiler does not depend
A. Tensile strength of the shell
B. Thickness of the shell
C. Diameter of the shell
D. Shear strength of shell material
E. None of the above
Answer: D.Shear strength of shell material
108. Total solid impurities in feed water for a boiler depend upon
A. Boiler pressure
B. Quantity of steam to be generated
C. Type of fuel available
D. Quantity of steam
E. None of the above
Answer: A.Boiler pressure
109. A cold short metal is
A. One that can not be heated above 500?C
B. One that cannot be welded
C. One that cannot be worked under the hammer or by rolling or bent when cold without racking at the edges
D. One that cannot be easily rolled or bent at low temperatures
E. None of the above
Answer: B.One that cannot be welded
110. The thermal efficiency of steam turbine can be increased by
A. Increasing the pressure range
B. Reheating
C. Regeneration
D. All of the above
E. None of the above
Answer: D.All of the above
111. If the pressures at the beginning and end of compression in an Otto cycle engine are 1 kg/cm2 and 8 kg/cm2 respectively the air standard efficiency will be
A. 45%
B. 50%
C. 57%
D. 50%
E. 40%
Answer: D.50%
112. In a reaction turbine which steam flows through the moving blades
A. Pressure reduces while velocity increases
B. Both velocity as well as pressure decreases
C. Pressure increases
D. Pressure increases while velocity reduces
E. Velocity increases
Answer: B.Both velocity as well as pressure decreases
113. Which of the following functions reduces the irreversibility of a cycle?
A. high speed operation
B. low exhaust pressures
C. regeneration
D. use of lower pressure
E. Carbon dioxide
Answer: C.regeneration
114. The intercept of Willian’s line on Y-axis at the origin, gives
A. Missing quantity
B. Frictional horse power
C. No load steam consumption
D. Idling speed
E. All of the above
Answer: D.Idling speed
115. In a throttle governed single cylinder steam engine 5 I.H.P. is developed when steam consumption is 50 kg per hour and 2 I.H.P. is developed when the steam consumption is 26 kg per hour. The steam consumptions when the engine develops 4 I.H.P. will be
A. 46
B. 42 kg
C. 40 kg
D. 38 kg
E. 37 kg
Answer: B.42 kg
116. The efficiency of a jet propulsion unit is generally high at altitudes of
A. 7500 metres
B. 1000 metres
C. 5000 metres
D. 9000 metres
E. More than 10,000 metres
Answer: E.More than 10,000 metres
117. Which of the following is not used as ignition accelerator for diesel engine fuel?
A. Ethyl nitrate
B. Methyl alcohol
C. Acetone peroxise
D. Isoamyl nitrate
E. All of the above
Answer: B.Methyl alcohol
118. The ideal output velocity of steam from a nozzle having an enthalpy drop of 100 kcal/kg will be
A. 1098 m/s
B. 1000 m/s
C. 600 m/s
D. 915 m/s
E. 789 m/s
Answer: D.915 m/s
119. In a four stroke engine if a valve opens 25? before B.D.C. and closes 10? after T.D.C. the valve should be
A. Puppet valve
B. Cam valve
C. Spring valve
D. Inlet valve
E. Exhaust valve
Answer: E.Exhaust valve
120. If the air clearance is removed in a carburettor engine the fuel air ratio will be
A. Higher
B. Lower
C. Not affected
D. Fluctuating
E. None of the above
Answer: B.Lower
121. A fan is being used under certain known conditions. If the speed of fan is doubled the air displaced by the fan
A. Will remain the same
B. Will be doubled
C. Will be four times the original displacement
D. will be either times the original displacement
E. None of the above
Answer: B.Will be doubled
122. The maximum temperature in a gas turbine is of the order of
A. 700?C
B. 2000?C
C. 2500?C
D. 1500?C
E. 1000?C
Answer: A.700?C
123. Which of the following is a part of reciprocating steam engine and not a part of steam turbine plant?
A. Condenser
B. Governor
C. Pressure gauge
D. Cross head
E. All of the above
Answer: D.Cross head
124. For same output and same compression ratio four stroke SI engines as compared to two stroke engines have
A. Higher fuel consumption
B. Lower thermal efficiency
C. Higher thermal efficiency
D. Higher exhaust temperatures
E. None of the above
Answer: C.Higher thermal efficiency
125. For the same temperature limits and heat input, the most efficient cycle is
A. Carnot
B. Otto
C. Diesel
D. Brayton
E. All of the above have same efficiency
Answer: A.Carnot
126. The power for the propulsion of ship is provided by
A. Diesel engines
B. Steam turbines
C. Either (A) and (B) above
D. Batteries
E. Any of the above
Answer: C.Either (A) and (B) above
127. The steam trap is used to
A. Superheat the steam
B. Separate condensate from steam
C. Convert superheated steam into the steam
D. Condense the steam
E. Add moisture to steam
Answer: B.Separate condensate from steam
128. Piston ring are plated with chromium, cadmium or phosphate to
A. Reduce wear and eliminate scuffing
B. Improve heat transfer
C. Improve surface finish
D. Prevent clogging
E. Reduce clearance, between rings and cylinder
Answer: A.Reduce wear and eliminate scuffing
129. More test is conducted on
A. Engines with two flywheels
B. Multi-cylinder engines
C. Single cylinder engines
D. High speed engines
E. Slow speed engines
Answer: B.Multi-cylinder engines
130. In oil burners air is supplied
A. To assist inflow of oil
B. To prevent clogging of burner
C. To improve combustion efficiency
D. To uniformly spray oil in combustion chamber
E. None of the above
Answer: C.To improve combustion efficiency
131. In a compression ignition engine higher combustion chamber wall temperature will
A. Reduce knocking tendency
B. Increase knocking tendency
C. Have no effect
D. Reduce exhaust temperature
E. None of the above
Answer: A.Reduce knocking tendency
132. Clapeyron equation is applicable
A. To systems in equilibrium
B. To change of boiling point
C. To change of melting point
D. For change of state when two phases are in equilibrium
E. All of the above
Answer: D.For change of state when two phases are in equilibrium
133. In a system if base load is same as maximum demand, the load factor will be
A. 1
B. 1 percent
C. 0.5 percent
D. Infinity
E. Zero
Answer: A.1
134. Reheating of steam for steam turbine cycle is done primarily to
A. Reduce dryness fraction of exhaust steam
B. Increase the pressure of steam in the condenser
C. Increase boiler chimney draught
D. Improve thermal efficiency of the plant
E. All of the above
Answer: D.Improve thermal efficiency of the plant
135. Morse test is conducted on
A. Multi-cylinder engines
B. Vertical engines
C. Horizontal engines
D. Vet engines
E. Single cylinder engines
Answer: A.Multi-cylinder engines
136. Capacitor kVA required to bring the power factor of a 500 kW load 70% to 85% would be
A. 100 kVA
B. 250 kVA
C. 300 kVA
D. 150 kVA
E. 200 kVA
Answer: E.200 kVA
137. The function of a condenser in a steam power plant is
A. To preheat feed water with exhaust steam
B. To condense feed water
C. To utilise heat of exhaust steam
D. To act as a heat sink
E. To reduce back pressure
Answer: E.To reduce back pressure
138. For diatomic gas flowing through a nozzle the critical pressure ratio is given by
A. 0.75
B. 1
C. 3.546
D. 0.528
E. 0.577
Answer: C.3.546
139. Suri-transmission is
A. hydro-mechanical
B. mechanical-electrical
C. Carbon dioxide
D. electro-pneumatic
E. hydro-pneumatic
Answer: A.hydro-mechanical
140. The temperature of the blades of a gas turbine may be closer to
A. 350?C
B. 212?C
C. 1200?C
D. 600?C
E. 100?C
Answer: C.1200?C
141. Compression ratio for diesel engines is generally in the range
A. 25 to 30
B. 5 to 10
C. 22 to 25
D. 14 to 22
E. 10 to 14
Answer: D.14 to 22
142. In case of pressure compounded impulse turbine, for the steam while flowing through the nozzle of second stage
A. Pressure drops while velocity increases
B. Pressure increases while velocity decreases
C. Pressure and velocity both increase
D. Pressure increases
E. Pressure and velocity both decrease
Answer: A.Pressure drops while velocity increases
143. Which spark plug will have lower heat rating
A. W 350 T1
B. W 300 T1
C. W 95 T1
D. W 145 T1
E. W 225 T1
Answer: C.W 95 T1
144. In a petrol engine fuel lock generally occurs in
A. suction manifold
B. Carbon dioxide
C. inlet valve
D. Pump
E. gauge lines
Answer: D.Pump
145. As per IS specifications the endurance test for engines is conducted for
A. 500 hours
B. 1000 hours
C. 100 hours
D. 300 hours
E. 200 hours
Answer: A.500 hours
146. In a pumping installation the suction line is is 4 metre long and suction pipe diameter is 100 mm. Now if the suction pipe is replaced by a pipe combination consisting of 2 metres of 100 mm diameter pipe joined with 2 metres of 150 mm diameter pipe, the suction heat will become
A. 6 metres
B. 4 metres
C. 2 metres
D. 1 metre
E. None of the above
Answer: B.4 metres
147. Standard air is air at
A. Atmospheric conditions at any specific location
B. 1 kg/cm2 and atmospheric temperature (Relative humidity of 64%)
C. 1 kg/cm2 and 20?C (Relative humidity of 36%)
D. 1 kg/cm2 and 0?C (Relative humidity of 36%)
E. None of the above
Answer: A.Atmospheric conditions at any specific location
148. Which of the following is not needed in case of magneto ignition?
A. Coil
B. Capacitor
C. Distributor
D. Battery
E. Spark plug
Answer: D.Battery
149. During detonation in a petrol engine
A. The rate of speed variation is high
B. The rate of exhaust discharge is high
C. The rate of temperature rise is high
D. The rate of pressure rise is high
E. None of the above
Answer: D.The rate of pressure rise is high
150. Volume of air at 27?C is 2 cu-m. What will be the volume at 327?C
A. 3 cm-m
B. 12 cm-m
C. 4 cu-m
D. 2 cu-m
E. 8 cu-m
Answer: C.4 cu-m
151. The air standard efficiency of a Diesel engine depends on
A. Speed
B. Torque
C. Thermodynamic properties of working fluid
D. Cetane value of fuel used
E. Compression ratio
Answer: E.Compression ratio
152. The size of a steam engine is 200 x 250 – 300 r.p.m. In this 200 indicates
A. Shaft diameter
B. Steam pressure in 1bs/sq. in.
C. Piston stroke
D. Horse power
E. Cylinder bore
Answer: E.Cylinder bore
153. In multistages turbines by introducting reheating
A. Thermal efficiency improves
B. The output of turbine increases
C. Work done by compressor reduces
D. The ratio compressor compressor work/turbine output decreases
E. None of the above
Answer: A.Thermal efficiency improves
154. In order to reduce wear and eliminate scuffing, piston ring in internal combustion engines are
A. Made of soft material
B. Provided with grooves
C. Lubricated thoroughly
D. Made of square section
E. Plated with chromium, cadmium or phosphate
Answer: E.Plated with chromium, cadmium or phosphate
155. The ends of piston rod in steam engines are connected to
A. Connecting rod and cross-head
B. Crankshaft and cross-head
C. Piston and crankshaft
D. Piston and cross-head
E. Connecting rod and crankshaft
Answer: D.Piston and cross-head
156. One horse power-hr is equal to
A. 1 kWh
B. 632 kcal
C. 100,000 kJ
D. 107 Joules
E. None of the above
Answer: B.632 kcal
157. Which of the following boiler uses exhaust of the engine to produce draught?
A. Lamont boiler
B. Cornish boiler
C. Babcock and wilcox boiler
D. Lancashire boiler
E. Locomotive boiler
Answer: E.Locomotive boiler
158. In jet engine the compression ratio
A. Varies with altitude
B. Varies with speed
C. Varies as square of speed
D. Remains constant
E. None of the above
Answer: C.Varies as square of speed
159. Pour point is the temperature at which oil
A. Starts cracking
B. Will start flowing
C. Barely flows
D. Will ignite
E. Will give off vapours enough for ignition
Answer: C.Barely flows
160. Which one of the following factors will not assist in smooth running of a compression ignition engine?
A. Moderate rate of pressure rise
B. Short delay period
C. Minimum of after burning
D. High ignition temperature of fuel
E. None of the above
Answer: D.High ignition temperature of fuel
161. In case of an opposed piston engine the combustion chamber
A. Is not provided
B. Is formed between two piston tops
C. Is provided towards crank case side
D. Is fitted outside the cylinder
E. None of the above
Answer: B.Is formed between two piston tops
162. Specific heat is
A. The amount of heat required to raise the temperature of a unit quantity of substance through 1?C
B. The amount of heat requred to change the state or condition under which a substance exists without changing its temperature
C. The ratio of quantity of heat required to raise the temperature of a given weight of any substance through 1?C to the quantity of heat required to raise the temperature of same weight of water through 1?C
D. The heat sensed by a mercury thermometer
E. None of the above
Answer: C.The ratio of quantity of heat required to raise the temperature of a given weight of any substance through 1?C to the quantity of heat required to raise the temperature of same weight of water through 1?C
163. In a diesel engine the injection pressure is of the order of
A. 1500 kg/cm2
B. 100 kg/cm2
C. 1000 kg/cm2
D. 40 kg/cm2
E. 500 kg/cm2
Answer: B.100 kg/cm2
164. If a water cooled compressor knocks during operation, the probable cause cannot be
A. Loose valve
B. Air filter choked
C. Too much clearance in crank pin
D. Excess cooling in intercooler
E. Loose flywheel or pulley
Answer: D.Excess cooling in intercooler
165. Thermal efficiency of a compression ignition engine may be of the order of
A. 35%
B. 50%
C. 20%
D. 75%
E. 70%
Answer: A.35%
166. In centrifugal pumps suction head is
A. Vertical distance from supply level to pump centre line pump being level
B. (A) Above less suction friction heat
C. (A) Above less velocity heat
D. Any of the above
E. None of the above
Answer: C.(A) Above less velocity heat
167. Maintenance requirements are least in case of
A. Electric locomotives
B. Carbon dioxide
D. Diesel locomotives
E. Steam locomotives
Answer: A.Electric locomotives
168. The higher the temperature required to ignite diesel fuel,
A. Lower the octane number
B. Carbon dioxide
C. Lower the cetane number
D. Higher the cetane number
E. the higher the octane number
Answer: C.Lower the cetane number
169. In pumped storage systems, water is pumped
A. Upstream during peak load periods
B. Upstream during off peak periods
C. Upstream during off season
D. None of the above
E. None of the above
Answer: B.Upstream during off peak periods
170. The supercharging of diesel engine is done mainly to
A. Cool the engine
B. Increase the life of the engine
C. Increase the power output
D. Increase the speed
E. Reduce the cnoise from the engine
Answer: C.Increase the power output
171. In Eicher tractor the engine is
A. Air cooled
B. Horizontal
C. Multi-cylinder type
D. Low compression ratio petrol engine
E. Constant speed engine
Answer: A.Air cooled
172. Air fuel ratio in a petrol engine fitted with dirty air cleaner as compared to that with clean air clearance will be
A. Not affected
B. Higher
C. Lower
D. Fluctuating
E. Depends on load
Answer: C.Lower
173. Crankshafts are generally
A. Turned from bar stock
B. Die cast
C. Sand cast
D. Forged
E. Cold headed
Answer: D.Forged
174. In a condensing steam engine
A. Exhaust steam is condensed in condenser
B. Exhaust steam is not recirculated
C. Steam condenses as soon as it leaves the cylinder
D. Condensed steam is supplied
E. Steam condenses inside cylinder
Answer: A.Exhaust steam is condensed in condenser
175. The Apparatus used for the determination of calorific value of solid fuel is
A. Bunsen’s apparatus
B. Photo calorimeter
C. Bomb calorimeter
D. Releigh apparatus
E. Osrat’s apparatus
Answer: C.Bomb calorimeter
176. Stuffing box is provided in
A. Condensing steam engines
B. Non-condensing steam engines
C. High speed steam engines
D. Single acting steam engines
E. Double acting steam engines
Answer: E.Double acting steam engines
177. An exciter is a
A. D.C. motor
B. D.C.generator
C. A.C.generator
D. Synchronous motor
E. None of the above
Answer: B.D.C.generator
178. An engine operates at 1440 rpm under load whereas no load speed is 1500 rpm. The percentage speed drop of governor will be
A. 2%
B. 3%
C. 4%
D. 10%
E. 6%
Answer: C.4%
179. In a Bomb calorimeter the fuel to be tested is burnt
A. At constant volume
B. At constant pressure
C. There is no consideration of volume or pressure
D. In open atmosphere
E. At constant temperature
Answer: A.At constant volume
180. Which fuel will have least air consumption during combustion
A. Spirit
B. Benzol
C. Diesel fuel oil
D. Gasoline
E. Lubricating oil
Answer: A.Spirit
181. Movement of air inside engine cylinder does not help in
A. Distribution of fuel
B. Mixing of fuel with air
C. Reduction of after burning
D. Reducing noise
E. None of the above
Answer: D.Reducing noise
182. In a Lancashire boiler, the economiser is located
A. Before air preheater
B. After air preheater
C. Between feed pump and boiler
D. At any of the above locations
E. None of the above locations
Answer: A.Before air preheater
183. Iso-octane has octane number of
A. 100
B. 0
C. 50
D. 80 to 85
E. More than 100
Answer: A.100
184. Freezing point of petrol is around
A. ?4?C
B. ?30?C
C. 10?C
D. ?13?C
E. 0?C
Answer: B.?30?C
185. 1 Torr is equivalent to
A. 1 mm Hg
B. 13.6 cm of water column
C. 760 mm of water
D. 760 mm of Hg
E. None of the above
Answer: A.1 mm Hg
186. The most effective air cleaner for diesel engines is
A. Whirl type
B. Oil bath type
C. Dry type
D. Rope type
E. Wet type
Answer: B.Oil bath type
187. An economiser is installed in a boiler plant primarily to
A. Increase steam pressure
B. Increase rate of steam evaporation
C. Superheat the steam
D. Purify boiler feed water
E. Reduce fuel consumption
Answer: E.Reduce fuel consumption
188. The equilibrium conditions between supersaurated vapour and a cooled liquid surface are expressed in
A. Dalton’s equation
B. Napier’s equation
C. Kelvin Helmhotz equation
D. Clapcyron’s equation
E. Calender’s equation
Answer: C.Kelvin Helmhotz equation
189. Most of the heat generated in I.C. engines is transferred to surrounding medium by
A. Conduction only
B. Convection only
C. Conduction and convection
D. Radiation only
E. None of the above
Answer: C.Conduction and convection
190. Vapour lock is
A. Supply of liquid fuel particles to engine in maixture
B. Excess fuel supply to engine due to faster evaporation
C. Complete or partial stoppage of fuel supply due to vaporisation of fuel in supply steam
D. Lock of vaporization of fuel to atomspheric pressure
E. Locking carburettor jets due to vapour pressure
Answer: C.Complete or partial stoppage of fuel supply due to vaporisation of fuel in supply steam
191. The steam pressure in a pass out turbine may be expected to be in the range
A. 10 kg/cm2 to 20 kg/cm2
B. 100 kg/cm2 to 150 kg/cm2
C. 150 kg/cm2 to 300 kg/cm2
D. 75 kg/cm2 to 100 kg/cm2
E. 40 kg/cm2 to 75 kg/cm2
Answer: A.10 kg/cm2 to 20 kg/cm2
192. A regenerator in a gas turbine
A. Reduces heat loss in exhaust
B. permits use of higher compression ratio
C. Improves thermal efficiency
D. Permits use of fuels of inferior quality
E. None of the above
Answer: C.Improves thermal efficiency
193. Higher proportion of residual gases in the cylinder would mean
A. Higher volumetric efficiency
B. Lower volumetric efficiency
C. No change in volumetric efficiency
D. Depends on other factors
E. None of the above
Answer: B.Lower volumetric efficiency
194. Low grade fuels have
A. Low moisture content
B. Low ash content
C. Low calorific valve
D. Low carbon content
E. None of the above
Answer: C.Low calorific valve
195. A gas turbine cycle with regenerator has a thermal efficiency of 26%. If intercooler and reheater are also introduced what could be expected thermal efficiency
A. 50%
B. 10%
C. 60%
D. 40%
E. 30%
Answer: E.30%
196. Free piston engines find application in
A. Compressed air supply
B. Mining installations
C. Gas turbines
D. Supercharging of diesel engines
E. None of the above
Answer: C.Gas turbines
197. In case of supersonic flow through the nozzle, when the cross-section increases in the direction of flow
A. The velocity will decrease in the direction of flow
B. The pressure will increase in the direction of flow
C. The velocity will increase while the pressure will decrease in the direction of flow
D. The velocity will decrease while the pressure will increase in the direction of flow
E. None of the above
Answer: C.The velocity will increase while the pressure will decrease in the direction of flow
198. The performance of air compressor at high altitudes as compared to that at sea level will be
A. Will depend upon temperature of air
B. Will depend on type of compressor
C. Better
D. Same
E. Inferior
Answer: E.Inferior
199. To avoid moisture trubles, the branch connection from compressed air line are taken from
A. Top side
B. Bottom side
C. Left side
D. Any side
E. Right side
Answer: A.Top side
200. Which turbine has identical fixed and moving blades
A. Carbon dioxide
B. De Laval turbine
C. Parson’s reaction turbine
D. Rateau’s turbine
E. Hero’s turbine
Answer: C.Parson’s reaction turbine
201. A radiation pyrometer is used for temperatures
A. Upto 100?C
B. Below 100?C
C. Above 500?C
D. 250 – 500?C
E. 100 – 250?C
Answer: C.Above 500?C
202. The processes in a Rankine cycle are
A. Two isothermal and two isentropic
B. Two isothermal and two polytropic
C. Two isothermal and two isobaric
D. One constant pressure, one constant volume and two polytropic
E. None of the above
Answer: E.None of the above
203. The function of a receiver in compressor installations is
A. To collect compressed air
B. To dempen pulsations or pressure waves incompressor discharge
C. To reduce temperature of compressed air
D. To reduce moisture content of compressed air
E. None of the above
Answer: B.To dempen pulsations or pressure waves incompressor discharge
204. In an analysis report of a sample of coal, the percentage of one of the constituents is specified as 2.5%. This constituent could be
A. Carbon steel
B. Ash
C. Moisture
D. Sulphur
E. None of the above
Answer: D.Sulphur
205. Apart from reducing friction and cooling the surfaces, the function of lubricant in I.C. engines is
A. To improve thermal efficiency
B. To clean the surfaces by carrying away the carbon and metal particles cansed by wear
C. To reduce noise
D. To reduce vibrations
E. None of the above
Answer: B.To clean the surfaces by carrying away the carbon and metal particles cansed by wear
206. During throttle governing of steam engines
A. Cut off of the engine cylinder changes according to the load
B. Pressure of steam supplied does not change with the load
C. Thermal efficiency of the engine reduces
D. Mechanical efficiency of the engine increases
E. None of the above
Answer: C.Thermal efficiency of the engine reduces
207. The efficiency of jet engine is higher at
A. Lower altitudes
B. Higher altitude
C. Low speeds
D. High speeds
E. None of the above
Answer: B.Higher altitude
208. In a compression ignition engine the fuel consumption will increase if the back (exhaust) pressure is
A. Decreased
B. Increased
C. Does not have any effect
D. Depends on other factors
E. None of the above
Answer: B.Increased
209. If petrol is supplied to a diesel engine
A. The engine will run at high speeds
B. The engine will run with excessive vibrations
C. The engine will explode
D. The engine will run with high knocking
E. The engine will not run
Answer: D.The engine will run with high knocking
210. A sample of water having pH value of 7 is
A. Acidic
B. Alkaline
C. Neutral
E. None of the above
Answer: C.Neutral
211. Which of the following has the lowest pressure in a petrol engine?
A. Gases during power stroke
B. Mixture at the end of compression stroke
C. Mixture at the beginning of suction stroke
D. Mixture at the end of suction stroke
E. Gases during exhaust stroke
Answer: D.Mixture at the end of suction stroke
212. The discharge of hydrocarbons from an automobile exhaust is minimum when the vehicle is
A. Decelerating
B. Cruising at high speeds
C. Cruising at low speeds
D. Accelerating
E. Idling
Answer: E.Idling
213. Load curve is the plot of
A. Load versus generatng capacity
B. Load versus current
C. Load versus time
D. Load versus cost of power
E. None of the above
Answer: C.Load versus time
214. With reference to a safety valve the blow down pressure is the pressure at which
A. Valve opens
B. Valve closes after opening
C. Valve opens initially
D. Valve spring pressure is adjusted
E. None of the above
Answer: B.Valve closes after opening
215. A four wheel drive automobile has
A. Four stroke engine
B. Air cooled engine
C. Four flywheels
D. Four cylinders
E. Two differentials
Answer: E.Two differentials
216. The work done in compressing 1 kg of air in compression will be least when the value of index is
A. 1.1
B. 1
C. 1.2
D. 1.41
E. 1.5
Answer: B.1
217. Separators are generally used in air compressor installations
A. Between after cooler and receiver
B. Before first stage suction
C. Before intercooler
D. After intercooler
E. None of the above
Answer: A.Between after cooler and receiver
218. For the same maximum pressure and heat input, the most efficient cycle is
A. Diesel
B. 5 to 10 percent
C. Brayton
D. Otto
E. Dual
Answer: C.Brayton
219. In compression ignition engines swirl is
A. Circular motion imparted to gases after combustion
B. Circular motion imparted to suction air
C. Radial motion imparted to fuel air mixture
D. Directional movement of fuel spray
E. None of the above
Answer: B.Circular motion imparted to suction air
220. Which of the following acts as a step up transformer in the ignition circuit of a petrol engine?
A. Battery
B. Coil
C. Plug
D. Distributor
E. Magneto
Answer: A.Battery
221. Tidal power is the power generated from
A. Raw sea water
B. Waves of the ocean
C. Rise and fall tides
D. Thermal energy of ocean water
E. Chemicals in sea water
Answer: C.Rise and fall tides
222. Percentage improvement in power in case of a four stroke diesel engine with the help of a supercharger may be expected in the range
A. 25
B. 35
C. 75
D. 50
E. 100
Answer: C.75
223. Thermal efficiency of a spark ignition engine at full load usually is in the range
A. 30 to 35 percent
B. 50 to 70 percent
C. 70 to 90 percent
D. 10 to 25 percent
E. 5 to 10 percent
Answer: A.30 to 35 percent
224. A Lungistrom turbine is
A. Impulse turbine
B. Reaction turbine
C. Outward radial flow turbine
D. Inward flow impulse reaction turbine
E. None of the above
Answer: C.Outward radial flow turbine
225. Diesel engine has air fuel ratio of 30 ; 1 during idling. A petrol engine can also work on such mixture provided
A. Ignition timing is changed
B. Carburettor is modified
C. Dannot run as it is impossible
D. Runs smoothly at lower speeds only
E. Engine is suitably modified
Answer: C.Dannot run as it is impossible
226. The amount of exhaust gases in clearance space left after exhaust stroke, varies with
A. Clearance volume
B. Carbon dioxide
C. air-fuel ratio of charger
D. Speed and load of the engine
E. Bore and length of cylinder
Answer: D.Speed and load of the engine
227. Out of the following diesel engine the minimum air consumption per B.H.P. will be in
A. 50%
B. 4 stroke, air injection
C. 2 stroke, air injection
D. 2 stroke, mech, injection, pump, scavenging
E. 4 stroke, mech, injection
Answer: E.4 stroke, mech, injection
228. Enthalpy of a substance is defined as
A. The sum of internal energy and the work done in forcing unit mass of substance into an enclosure at the constant pressure at which the substance exists
B. Sum of sensible heat + latent heat of substance
C. Total heat content of substance above zero degree centigrade
D. Sensible heat of water + work done in forcing unit mass of substance into an enclosure at constant pressure at which the substance exists
E. None of the above
Answer: C.Total heat content of substance above zero degree centigrade
229. Endurance test for I.C. engines is conducted for
A. 1000 hours
B. 200 hours
C. 500 hours
D. 400 hours
E. 100 hours
Answer: C.500 hours
230. A system having connected load of 100 kW, peak load of 80 kW, base load of 20 kW and average load of 40 kW will have a load factor of
A. 60%
B. 40%
C. 75%
D. 80%
E. 50%
Answer: E.50%
231. The value of reheat factor in case of steam turbines is usually
A. 1.25 to 1.50
B. 1.02 to 1.06
C. 1.10 to 1.16
D. 1.75 to 2.50
E. 0.9 to 0.99
Answer: B.1.02 to 1.06
232. A fuel of octane rating 85 matches the antiknock qualities of mixture consisting of
A. 85% heptane + 15% octane
B. 85% octane + 15% heptane
C. 85% petrol + 15% diesel
D. 85% benzene + 15% methyl alcohol
E. 15% petrol + 85% diesel
Answer: B.85% octane + 15% heptane
233. A Wankel engine combines the advantages of
A. SI and CI engines
B. Carburction and fuel injection
C. Air cooled and reciprocating engines
D. Rotory and reciprocating engines
E. Axial flow and centrifugal compression
Answer: D.Rotory and reciprocating engines
234. Willian’s line is relevant to
A. Throttle controlled trbine
B. Nozzle controlled turbines
C. Impulse turbines
D. Reaction turbines
E. None of the above
Answer: A.Throttle controlled trbine
235. Starting motor in automobiles is generally
A. Induction motor
B. Synchronous motor
C. Squirrel cage motor
D. Shunt motor
E. Series motor
Answer: E.Series motor
236. Three states of matter are distinguished with repect to molecules by
A. Characteristics of the motion of molecules
B. The number
C. Energy of molecules
D. The atoms in molecules
E. The orientation of molecules
Answer: A.Characteristics of the motion of molecules
237. Tenacity is the property of materials in which they
A. Resist indentation
B. Resist rupture
C. Resist shearing
D. Resist deformation
E. None of the above
Answer: B.Resist rupture
238. The horse power of engine for a ship is of the order to
A. 10,000 to 40,000
B. 50 to 100
C. 1000 to 5000
D. 100 to 500
E. 500 to 1000
Answer: A.10,000 to 40,000
239. As the steam flows in a subsonic nozzle, in which the cross-section is decreasing in the direction of flow
A. The velocity will decrease in the direction of flow
B. The pressure will increase in the direction of flow
C. The velocity will decrease while pressure will decrease in the direction of flow
D. The velocity will increase while pressure will decrease in the direction of flow
E. None of the above
Answer: D.The velocity will increase while pressure will decrease in the direction of flow
240. White smoke from a diesel engine can be expected during
A. Start up or idling
B. High speed operation
C. High load operation
D. All of the above
E. None of the above
Answer: A.Start up or idling
241. Total sulphur content in a diesel fuel oil must not exceed
A. 0.10%
B. 0.01%
C. 0.05%
D. 0.50%
E. 1%
Answer: D.0.50%
242. Air consumption of a four-stroke diesel engine per rated BHP/hr will be
A. 20 kg
B. 1 kg
C. 5 – 7 kg
D. 10 – 14 kg
E. 15 kg
Answer: C.5 – 7 kg
243. In spark ignition engines the knocking tendency decreases
A. As compression ratio is reduced
B. By controlling air/fuel mixture
C. By controlling ignition timing
D. By controlling exhaust temperatures
E. None of the above
Answer: A.As compression ratio is reduced
244. Water and sediments in a diesel fuel oil must not exceed.
A. 0.50%
B. 0.01%
C. 1%
D. 0.10%
E. 0.05%
Answer: E.0.05%
245. Rankine cycle efficiency for fixed steam temperature of any volume upto critical temperature will be maximum for steam pressure of
A. 250 kg/cm2
B. 100 kg/cm2
C. 200 kg/cm2
D. Critical pressure
E. 203.5 kg/cm2
Answer: D.Critical pressure
246. A certain gas occupies 2 cu-m at a temperature of 400?C. It receives heat at constant pressure till its temperature is doubled. The change in volume would be
A. 0.19 cu-m
B. 3.8 cu-m
C. 0.038 cu-m
D. 0.019 cu-m
E. 3.188 cu-m
Answer: E.3.188 cu-m
247. If the power factor of an electrical system is unity, it means
A. Efficiency is least
B. Entire power is consumed in reactive power
C. Entire power pulls the load
D. Equipment is running properly
E. Magnetism generated within the equipment is negligible
Answer: C.Entire power pulls the load
248. A fixed quantity of heat is to be added to a system under specific conditions. The process in which the entropy change will be maximum is
A. Constant pressure process
B. Constant volume process
C. Constant temperature process
D. Isentropic process
E. None of the above
Answer: C.Constant temperature process
249. Air standard efficiency of an I.C. engine depends on
A. Compression ratio
B. Speed of operation
C. Fuel used
D. Torque
E. All of the above
Answer: A.Compression ratio
250. Which of the following is false statement?
A. Fuel consumption of engine increases if silencer is choked
B. Fuel consumption of engines decreases if air filter is choked
C. Fuel consumption increases if exhaust valve is burnt
D. Fuel consumption increases if lean mixture is supplied
E. All of the above
Answer: D.Fuel consumption increases if lean mixture is supplied
251. Which of the boiler provides superheated steam?
A. Locomotive boiler
B. Lancashire boiler
C. Cornish boiler
D. All of the above
E. None of the above
Answer: A.Locomotive boiler
252. Which of the following particles will be smallest in size?
A. Drizzle
B. Mist
C. Smog
D. Fog
E. Rain
Answer: C.Smog
253. Dew point temperature is an indication of
A. Condition of air
B. Condition of moisture in air
C. Dryness of air
D. Lowest temperature where air and water vapour start separating
E. Moisture constant of air
Answer: D.Lowest temperature where air and water vapour start separating
254. High air-fuel ratio in gas turbines
A. Reduces the exhaust temperature
B. Improves thermal efficiency
C. Increases power output
D. Restricts damage to turbine blades
E. None of the above
Answer: A.Reduces the exhaust temperature
255. If a steam injector fails to lift the water the trouble may not be due to
A. Too low steam pressure for list
B. Water pipe clogged
C. Water supply to cold
D. End of water pipe not submerged
E. None of the above
Answer: C.Water supply to cold
256. Working in the cryogenic range means dealing with temperatures
A. Below absolute zero
B. Below zero degree centigrade
C. Between – 190?C and absolute zero
D. Prevailing normally in the atomsphere
E. Between zero degree centigrade and 190?C
Answer: C.Between – 190?C and absolute zero
257. The sulphur content in diesel oil should not exceed
A. 15%
B. 5%
C. 12%
D. 1%
E. 10%
Answer: D.1%
258. Which of the following will not be seen in a boiler using pulverised fuel?
A. Chain in great stoker
B. Feed pump
C. Economiser
D. Superheater
E. Chimney
Answer: A.Chain in great stoker
259. The governor for steam turbine is driven by
A. Main shaft
B. Separate motor
C. Belt drive
D. Feed pump motor
E. None of the above
Answer: A.Main shaft
260. Air preheater in a boiler will be invariably located between
A. Condenser and feed water pump
B. Water treatment plant and furnace
C. Boiler furnace and chimney
D. Economiser and feed pump
E. Forced draft fan and furnace
Answer: E.Forced draft fan and furnace
261. A run-of-river hydro-electric station is one which is
A. Located on a small river
B. Located on a river which does not flow throughout the year
C. Located on a steam flow without water storage
D. Locted on a steam flow with large water storage
E. None of the above
Answer: C.Located on a steam flow without water storage
262. After cooler is used to
A. Cool the air
B. Reduce the volume of air
C. To cause moisture and oil vapour to drop out
D. Remove impurities from air
E. None of the above
Answer: A.Cool the air
263. Brayton cycle cannot be used in reciprocating engines even for same compression rations and work output because
A. Large volume at low pressure cannot be efficiently harded in reciprocating engines
B. Brayton cycle is less efficient
C. Otto cycle is more efficient
D. Brayton cycle requires large air-fuel ratio
E. Brayton cycle is for slow speed engines only
Answer: A.Large volume at low pressure cannot be efficiently harded in reciprocating engines
264. A sample having pH value of 5 will be
A. Neutral
B. Acidic
C. Alkalino
E. None of the above
Answer: B.Acidic
265. The mean effective pressure of a diesel cycle having fixed compression ratio will increase if cut off ratio will
A. Increase
B. Decrease
C. Independent of CR
D. Depends on other factors
E. None of the above
Answer: A.Increase
266. Thermal efficiency of C.I. engines on weak mixtures is
A. Higher
B. Lower
C. Unaffected
D. Depends on other factors
E. None of the above
Answer: A.Higher
267. In order to achieve maximum possible fuel economy the design features which will be affected are
A. Volumetric efficiency
B. Compression ratio
C. Method of charging
D. Atomization
E. None of the above
Answer: D.Atomization
268. A negative loop in the P-V diagram of a petrol engine is due to
A. Carbon dioxide
B. Suction of air
C. pre-ignition
D. early opening of exnaust valve
E. detonation
Answer: D.early opening of exnaust valve
269. A compound pressure gauge measures
A. Average pressure
B. Positive and negative pressures
C. Compound pressures
D. Variable pressures
E. Complex pressures
Answer: B.Positive and negative pressures
270. A barN is
A. A unit of area
B. A unit of length
C. A unit of time
D. A unit of mass
E. None of the above
Answer: A.A unit of area
271. In isothermal compression
A. There is no gain internal energy
B. Temperature increses very slowly
C. There is no exchange of heat with environment
D. Entropy changes is zero
E. None of the above
Answer: A.There is no gain internal energy
272. In Parsons reaction turbine
A. The fixed and moving blades are identical
B. The velocity biagram is unsymmetrical about a vertical centre line
C. The degree of reaction is
D. The fixed blades are smaller in size as compared to moving blades
E. The fixed blades are larger in size compared to fixed blades
Answer: A.The fixed and moving blades are identical
273. For combustion of one kg of carbon the quantity of oxygen required (air contains 23% by wight of oxygen) is
A. 12 kg
B. 8 kg
C. 2.62 kg
D. 11.6 kg
E. 3.67 kg
Answer: C.2.62 kg
274. If a engine working on Otto cycle has its compression ratio raised from 5 to 6 the percentage increase in air standard efficiency will be
A. 4%
B. 10%
C. 6%
D. 8%
E. 1%
Answer: A.4%
275. For spark ignition engines fuel in order of decreasing knock tendency are
A. Paraffins, aromatics, naphthenes
B. Paraffins, naphthenes, armatics
C. Aromatics, paraffins, naphthenes
D. Naphthenes, aromatics, paraffins
E. Naphthenes, paraffins
Answer: B.Paraffins, naphthenes, armatics
276. Which of the following can have octane rating of more than 100?
A. Gobar gas
B. Normal petrol
C. Methyl alcohol
D. Benzol
E. Ethyl alcohol
Answer: D.Benzol
277. Normally the colour of exhaust from a diesel engine is
A. Bluish
B. Reddish
C. Violet
D. Black
E. Yellowish
Answer: D.Black
278. For initially dry and saturated steam flowing through a nozzle the volue of critical pressure ratio is given by
A. 0.577
B. 1
C. 0.528
D. 0.546
E. 0.75
Answer: A.0.577
279. Which of the following type of internal combustion engines uses rocker arms?
A. Radial engines
B. Side valve engines
C. Overhead valve engines
D. Stationary engines
E. All of the above
Answer: C.Overhead valve engines
280. In naturally aspirated engine the pressure inside cylinder at the end of suction stroke is
A. Less than atmospheric
B. Same as atmospheric
C. More than atmospheric
D. Depends on atmospheric conditions
E. None of the above
Answer: A.Less than atmospheric
281. The ash content in diesel oil should not exceed
A. 0.10%
B. 0.50%
C. 5%
D. 0.01%
E. 1%
Answer: D.0.01%
282. A hot short metal is
A. Brittle when heated
B. Brittle when cold
C. Ductile at low temperatures
D. Ductile at high temperatures
E. None of the above
Answer: A.Brittle when heated
283. In a SI engine the advancing of spark timing will
A. Increase knocking tendency
B. Reduce knocking tendency
C. Not have any effect
D. Depends on intensity of spark only
E. None of the above
Answer: A.Increase knocking tendency
284. Of the calorific value ranges given below which one is generally for coal?
A. 2500 – 4000 kcal/kg
B. 1000 – 2500 kcal/kg
C. 4000 – 7000 kcal/kg
D. 8000 – 12000 kcal/kg
E. 100 – 1000 kcal/kg
Answer: C.4000 – 7000 kcal/kg
285. The function of a piston rins in an internal combustion engine is
A. To prevent lubricating oil from entering the combustion space
B. To prevent leakage of combustion chamber products
C. To transfer heat from piston to cylinder walls
D. All of the above
E. None of the above
Answer: D.All of the above
286. Zeroth law of thermodynamics states that
A. Two systems are always in equilibrium
B. If two systems are in equilibrium the third system will also be in equilibrium
C. If two systems are in thermal equilibrium with a third system, then they are in equilibrium with each other
D. Two systems not in equilibrium with a third system are also not in equilibrium with each other
E. None of the above
Answer: C.If two systems are in thermal equilibrium with a third system, then they are in equilibrium with each other
287. For the same peak pressure and heat input
A. Otto cycle is more efficient
B. Diesel cycle is more efficient
C. Both are equally efficient
E. None of the above
Answer: B.Diesel cycle is more efficient
288. In a jet propulsion unit the products of combustion after passing through the gas turbine are discharged into
A. Recycled back to compressor
B. Atmosphere
C. Compressor
D. Vacuum
E. Discharge nozzle
Answer: E.Discharge nozzle
289. A D-slide valve is used in
A. Two stroke engines
B. Diesel engines
C. Petrol engines
D. Steam engines
E. Double acting engines
Answer: D.Steam engines
290. The Clapeyron equation is applicable for
A. System in equilibrium
B. Change of state
C. Change of state when two phases are in equilibrium
D. Change of state when water and water vapours are involved
E. None of the above
Answer: C.Change of state when two phases are in equilibrium
291. Speed drop is the
A. Drop in engine speed
B. Increasing in engine speed
C. Reduction in engine speed from no loads to full load
D. Change in engine speed while fuel supply remains the same
E. None of the above
Answer: C.Reduction in engine speed from no loads to full load
292. For reciprocating air compressor the law of compression desired is isothermal and that may be possible by
A. Very high speeds
B. very low speeds
C. any speed as speed does not affect the compression law
D. None of the above
E. Carbon dioxide
Answer: B.very low speeds
293. In a surface condenser near to the air pump suction the vacuum is 500 mm of mercury with 730 mm of mercury height in a barometer. The pressure near the air pump suction would be
A. 0.69 kg/sq-cm
B. 1.213 kg/sq-cm
C. 0.313 kg/sq-cm
D. 0.687 kg/sq-cm
E. 1230 mm Hg
Answer: A.0.69 kg/sq-cm
294. Which of the following fuel can be obtained by fermentation of vegetable matter?
A. Alcohol
B. Gasoline
C. Benzene
D. Carbon dioxide
E. Diesel
Answer: A.Alcohol
295. If performance of SI engines of different manufacture having different capacities, sizes and systems are to be compared the common parameter would be
A. Engine cylinder diameter
B. B.H.P.
C. Weight of engine
D. Speed
E. Mean effective pressure
Answer: E.Mean effective pressure
296. Which of the following is not a part of diesel engine?
A. Gudgeon pin
B. Air filter
C. Oil pump
D. Condenser
E. Lubricating oil filter
Answer: D.Condenser
297. Compression ratio for spark ignition engines varies in the range
A. 6 to 12
B. 20 to 25
C. 4 to 6
D. 25 to 30
E. 12 to 20
Answer: A.6 to 12
298. If a heat engine given an output of 3.5 kW and input is 10000 Joules per second, the thermal efficiency of the engine will be
A. 66?%
B. 35%
C. 30%
D. 65%
E. 55%
Answer: B.35%
299. Inlet valve of a IC engine remains open for
A. 180?
B. 250?
C. 300?
D. 150?
E. 280?
Answer: B.250?
300. The capacity of an automobile battery is expressed in terms of
A. Number of cells
B. Number of plate
C. Ampere hours
D. Amperes
E. Voltage
Answer: C.Ampere hours
301. Engines are supercharged
A. To increase engine durability
B. To increase specific power output
C. To increase air-fuel ratio
D. To improve heat transfer
E. To reduce combustion temperature
Answer: B.To increase specific power output
302. Thermodynamic equilibrium is completely defined by the specifications of the
A. Internal energy
B. Enthalpy
C. Generalized displacements
D. All above together
E. None of the above
Answer: D.All above together
303. Within the boiler the temperature of steam is highest in
A. Water drum
B. water tubes
C. Superheater outlet
D. Water walls
E. Superheater inlet
Answer: C.Superheater outlet
304. A closed vessel contains air at 1.2 ata and 57?C. The pressure of air in the vessel if the contents of the vessel are cooled to 37?C would be
A. 1.2 ata
B. 1.127 ata
C. 2.327 ata
D. 0.563 ata
E. 0.073 ata
Answer: B.1.127 ata
305. Which one of the following acts as ignition accelerator for C.I. engines fuel
A. Acetone peroxide
B. Hydrogen peroxide
C. None of above
D. n heptane
E. Armatic compounds
Answer: A.Acetone peroxide
306. Paraffins in petrol have the general formula
A. Cn Hn
B. Cn H2n + 2
C. Cn H2n – 4
D. Cn H2n
E. Cn H2n – 2
Answer: B.Cn H2n + 2
307. If an air cooled compressor gets over-heated during operation, the probable cause cannot be
A. Direction of rotation wrong
B. Valve strips broken
C. Leadage in intercooler
D. Insufficient lubricating oil
E. Intake fliter clogged
Answer: C.Leadage in intercooler
308. The phenomenon of hunting is associated with
A. Governors
B. Gears
C. Cloth mechanism
D. Carburetors
E. Tappet valves
Answer: A.Governors
309. The term regeneration is closely associated with
A. Steam engines
B. Steam turbines
C. Diesel engines
D. Gas engines
E. Wankel engines
Answer: B.Steam turbines
310. The air standard efficiency of a turbine cycle is 56.5%, which one of the following may be Carnot efficiency between the temperature limits of the cycle?
A. 75%
B. 64%
C. 50%
D. 100%
E. 56.50%
Answer: B.64%
311. A wankel engine is
A. Rotory engine
B. Turbine engine
C. Jet engine
D. Reciprocating engine
E. Hybrid engine
Answer: A.Rotory engine
312. The temperatures and pressures for boiler are given below. Which of these boilers can be classified as super-critical pressure boiler?
A. 250 psi, 150?C
B. 100 kg/cm2, 450?C
C. 10 kg/cm2, 150?C
D. 150 kg/cm2, 500?C
E. 218 kg/cm2, 540?C
Answer: E.218 kg/cm2, 540?C
313. Motor cycle not using deflector type piston usually utilise
A. Reverse flow scavanging
B. Ideal scavanging
C. Uniflow scavanging
D. Natural scavanging
E. Loop scavanging
Answer: A.Reverse flow scavanging
314. Direction of feed water is done because
A. It reduces weight of water to be handled
B. It reduced priming difficulties in feed pumps
C. It reduces corrosion caused by oxygen present in air
D. It reduces amount of heat required to convert water into steam
E. None of the above
Answer: C.It reduces corrosion caused by oxygen present in air
315. The dryness fraction of steam within a turbine is usually not allowed to fali below
A. Unity
B. 0.45
C. 0.8
D. 0.9
E. 0.99
Answer: D.0.9
316. Which of the following is an accessory for a boiler?
A. Stop valve
B. Feed check valve
C. Safety valve
D. Feed pump
E. Blow off cock
Answer: D.Feed pump
317. The molecules move in a solid
A. At random
B. Back and forth like tiny pendulum
C. In irregular motion
D. In circular motion
E. None of above
Answer: B.Back and forth like tiny pendulum
318. In all a four stroke four cylinder engine will have how many valves?
A. 8
B. 16
C. none
D. 4
E. Carbon dioxide
Answer: A.8
319. Latent heat is
A. Heat required to change the state or condition under which the substance exists
B. Heat that does not follow first law of thermodynamics
C. Heat required to change the state of substance from liquid state to solid state
D. Heat required to change the substance from solid to gaseous state
E. Heat cannot be detected
Answer: A.Heat required to change the state or condition under which the substance exists
320. Steam consumption per kWh of electricity generated in a modern power plant is of the order of
A. 10 -12 kgs
B. 5 – 7 kgs
C. 8 – 10 kgs
D. 2 – 4 kgs
E. 1 – 2 kgs
Answer: B.5 – 7 kgs
321. In jet engines the compression ratio
A. Varies with square of speed
B. Remains constant
C. Varies with altitude
D. Depends on other factors
E. Varies with altitude
Answer: A.Varies with square of speed
322. An Orsat’s apparatus is used for
A. None of above
B. Gravimetric analysis of the flue gases
C. Volumetric analysis of the flue gas
D. Smoke density analysis of the flue gases
E. All of above
Answer: C.Volumetric analysis of the flue gas
323. Motoring test on I.C. engines is conducted to measure
A. I.H.P.
B. B.H.P.
C. Pumping horse power
D. Friction horse power
E. None of the above
Answer: D.Friction horse power
324. The turbidity in boiler feed water causes
A. Sludge
B. Scale
C. Corrosion
D. Embrittlement
E. None of the above
Answer: A.Sludge
325. Steam leaves the steam nozzle at
A. Low pressure and low velocity
B. Low pressure and high velocity
C. High pressure and low velocity
D. High pressure and high velocity
E. None of the above
Answer: B.Low pressure and high velocity
326. In diesel engines thermal efficiency may be expected in the range
A. 35 to 40 percent
B. 10 – 15 percent
C. 15 to 25 percent
D. 50 percent
E. 25 to 30 percent
Answer: A.35 to 40 percent
327. In reciprocating air compressor, the method of controlling the quantity of air delivered is done by
A. Clearance Control
B. Throttle Control
C. Blow-off Control
D. All of the above
E. Carbon dioxide
Answer: D.All of the above
328. Motor cycles generally have
A. Evaporative cooling system
B. Natural cooling engines
C. Ice cooled engines
D. Natural cooling engines
E. Air cooled engines
Answer: E.Air cooled engines
329. Crankcase dilution is
A. Dilution of fuel in crank case
B. Dilution of lubricating oil in crankcase
C. Dilution of mixture while passing through crankcase in two stroke engines
D. Addition of water in crankcase
E. None of the above
Answer: B.Dilution of lubricating oil in crankcase
330. In an analysis report of a sample of coal the percentage of one of the constituents is specified as 3.5%. This constituent could be
A. Carbon
B. Ash
C. Moisture
D. Sulphur
E. Any of the above
Answer: D.Sulphur
331. A plant costing Rs. 80,000 has a useful life of 12 years. The amount that should be saved annually to replace the equipment at the end of useful life with salvage value of Rs. 8,000 should be
A. Rs. 15000
B. Rs. 8000
C. Rs. 6000
D. Rs. 5000
E. Rs. 10000
Answer: C.Rs. 6000
332. In a spark ignition engine supercharging
A. Decreases knocking tendency
B. There is no effect on knocking
C. Increases knocking tendency
D. Knocking is affected by other factors
E. 1000 hours
Answer: C.Increases knocking tendency
333. A passout turbine generally operates on low pressure in the range
A. 10 – 20 kg/cm2
B. 100 – 150 kg/cm2
C. 20 – 50 kg/cm2
D. 150 – 300 kg/cm2
E. 50 – 100 kg/cm2
Answer: A.10 – 20 kg/cm2
334. In a reaction turbine while steam flows through the fixed blades
A. Velocity increases
B. Velocity decreases
C. Velocity increases while pressure drops
D. Pressure increases
E. Neither admission pressure nor cut off is varied
Answer: C.Velocity increases while pressure drops
335. For steam engine having a throttle governor, a straight line is obtained when the total weight of steam used per hour is plotted against the indicated horse power. This line is known as
A. Willian’s line
B. Clapeyron’s line
C. Bunsen line
D. Calender’s line
E. Hopson’s line
Answer: A.Willian’s line
336. Ignition accelerators are used primarily to
A. Reduce exhaust temperature
B. Convert carbon monoxide into carbon dioxide
C. Reduce combustion knock
D. Cool the engine cylinder
E. All of the above
Answer: C.Reduce combustion knock
337. A gas turbine power plant suits as
A. Peak load plant
B. Casual run plant
C. Base load plant
D. All of the above
E. None of the above
Answer: A.Peak load plant
338. In diesel engines, the accumulation of carbon in the cylinder increases
A. Mechanical efficiency
B. Volumetric efficiency
C. Ignition delay period
D. Effective compression ratio
E. Clearance volume
Answer: D.Effective compression ratio
339. Which of the following is the internal loss of a turbine?
A. None of above
B. Blade friction loss
C. Nozzle loss
D. All of above
E. Wheel friction loss
Answer: B.Blade friction loss
340. Which of the following is not a property of carbondioxide?
A. Non-toxic
B. Non-inflammable
C. Colourless
D. Pungent odour
E. None of the above
Answer: D.Pungent odour
341. A heat exchanger that can remove fixed quantity of heat from a system is available where should it be installed for best economy
A. Anywhere
B. As intercooler
C. After final stage compression
D. Depends upon size of installation
E. Prior to first stage compression
Answer: E.Prior to first stage compression
342. A fan is being operated in an environment for which information is available. Now if the fan speed is doubled, how will the static pressure vary
A. Eight times
B. No change
C. Sixteen times
D. Doubled
E. Four times
Answer: E.Four times
343. A 50 cfm compressor can
A. Compress 50 cu feet per min of free air
B. Compress 50 cu feet per min of standard air
C. Deliver 50 cu feet of compressed air at delivery pressure
D. Delivers 50 cu ft. per minute of compressed air
E. None of the above
Answer: A.Compress 50 cu feet per min of free air
344. A perfect heat engine works on the Carnot cycle between 1000?C and 200?C. The efficiency of the engine will be
A. 42.80%
B. 60%
C. 62.80%
D. 80%
E. 37.20%
Answer: C.62.80%
345. A gas turbine works on
A. Dual cycle
B. Brayton cycle
C. Carnot cycle
D. Otto cycle
E. Rankine cycle
Answer: B.Brayton cycle
346. In power station practice ‘spinning reserve’ is
A. Reserve generating capacity that is in operation but in service
B. Reserve generating capacity that is connected to bus and ready to take load
C. Reserve generating capacity that is available for service but not in operation
D. Capacity of the part of plant that remains under maintenance
E. None of the above
Answer: B.Reserve generating capacity that is connected to bus and ready to take load
347. Ash content of a diesel fuel oil should not exceed
A. 0.50%
B. 0.05%
C. 1%
D. 0.01%
E. 0.10%
Answer: D.0.01%
348. Injector is used to
A. Inject wet steam into superheater
B. Inject steam into steam engine cylinder
C. Inject secondary air in boiler furnace
D. Inject water boiler
E. Inject exhaust gases into chimney
Answer: D.Inject water boiler
349. A barn is a
A. Unit of momentum
B. Unit of time
C. Unit of area
D. Unit of length
E. Unit of mass
Answer: C.Unit of area
350. High steam and low water safety valve is not used on which of the following boiler?
A. Locomotive boiler
B. Cornish boiler
C. Cochran boiler
D. Lancashire boiler
E. All of the above
Answer: A.Locomotive boiler
351. Change in internal energy is least during
A. 25 to 30
B. Constant pressure process
C. Constant volume process
D. Adiabatic process
E. Isothermal process
Answer: E.Isothermal process
352. Which of the following is not a petroleum product?
A. Methylated spirit
B. Lubricating oil
C. Kerosene
D. Carbon dioxide
E. Petrol
Answer: A.Methylated spirit
353. Thermal efficiency of a standard Otto cycle for a compression ratio 5.5, will be
A. 100%
B. 47.50%
C. 20%
D. 35.40%
E. 50%
Answer: E.50%
354. The calorific value of methane can be determined by
A. Bomb calorimeter
B. Bunsen’s calorimeter
C. Orsat’s apparatus
D. Exhaust gas calorimeter
E. None of the above
Answer: E.None of the above
355. The fact that the product of pressure and volume of a fixed amount of gas is approximately a constant value is known as
A. Charle’s law
B. Gay Lusac’s law
C. Dalton’s law
D. Lewis law
E. None of the above
Answer: E.None of the above
356. Air fuel ratio for a jet engine is of the order of
A. 60;1
B. 15;1
C. 600;1
D. 20;1
E. 10;1
Answer: A.60;1
357. A steam nozzle is said to be choked when
A. Pressure at throat is equal to steam supply pressure
B. Throat gets clogged
C. Flow is at maximum value of critical exit pressure
D. Steam flow through nozzle ceases
E. Pressure at throat is less than the exit pressure
Answer: E.Pressure at throat is less than the exit pressure
358. In a four stroke cycle the minimum temperature inside the engine cylinder occurs
A. At the end of exhaust stroke
B. At the end of suction stroke
C. At the end of compression stroke
D. At the beginning of exhaust stroke
E. At the beginning of suction stroke
Answer: B.At the end of suction stroke
359. According to Charle’s law
A. At constant pressure the volume of a gas is proportional to its absolute temperature
B. At constant temperature, pressure is proportional to temperature
C. At constant temperature, pressure of a gas is proportional to its volume
D. At constant volume the absolute pressure is proportional to the temperature
E. None of the above
Answer: A.At constant pressure the volume of a gas is proportional to its absolute temperature
360. Prony brakes are used for testing
A. Slow speed engines
B. High speed engines
C. Engines with small flywheel
D. Small engines
E. Large capacity engines
Answer: D.Small engines
361. In wet dry lubrication of diesel engines
A. Oil is splashed
B. Oil is splashed and pumped to various points
C. Oil is pumped to various points
D. All of the above
E. None of the above
Answer: C.Oil is pumped to various points
362. In a velocity compounded impulse turbine, while steam flows through the second row of moving blades
A. The velocity increases
B. The velocity reduces
C. Both velocity as well as pressure increase
D. The velocity remains constant
E. The pressure remains constant
Answer: B.The velocity reduces
363. Ignition accelerators are often used for
A. Diesel engine fuels
B. Petrol engine fuels
C. Gas turbine fuels
D. Gas generators
E. All of the above
Answer: B.Petrol engine fuels
364. Which one of the following statements is incorrect
A. Combustion is the processes of heat liberation
B. Combustion is a chemical reaction
C. Combustion is rapid oxidation
D. All of the above
E. None of the above
Answer: D.All of the above
365. During idling in a compression ignition engine the air fuel ratio may be of the order of
A. 5
B. 20
C. 10
D. 15
E. 30
Answer: E.30
366. Solid injection in diesel engines implies
A. Use of solid fuels
B. Supply of fuel in the form of solid
C. Injecting fuel with lubricating oil
D. Injecting fuel and air simultaneously
E. Injecting fuel without air
Answer: E.Injecting fuel without air
367. Which fuel has maximum resistance to detonation
A. Alcohol
B. n-Heptane
C. Toulene
D. Iso-octane
E. Benzene
Answer: D.Iso-octane
368. The level of oil in engine cylinder should be checked when the engine is
A. Not running
B. Running
C. During starting
D. During cranking
E. None of the above
Answer: A.Not running
369. The molecular weight of a mixture containing 20% oxygen, 20 percent nitrogen and 60 percent carbon dioxise on volume bases will be nearly
A. 38.4
B. Carbon dioxide
C. 41.4
D. 29.9
E. 33.3
Answer: A.38.4
370. Dissociation is
A. Process of heat liberation in which no flame exist
B. Same is combustion
C. Combustion without heat
D. Slow combustion
E. Smokeless combustion
Answer: B.Same is combustion
371. Thermodynamic processes are those
A. Where a difference is observed in any macroscopic property of the system between different times or state
B. Where a difference is observed in any microscopic property of the system between different times or state
C. Which occurs in the direction of an intensive property or driving force contained within the system
D. Which require an agency outside the system to force the process
E. None of the above
Answer: A.Where a difference is observed in any macroscopic property of the system between different times or state
372. A Lungistrom turbine is a
A. Radial flow reaction turbine
B. Axial flow reaction turbine
C. Radial flow impulse turbine
D. Mixed flow impulse turbine
E. None of the above
Answer: A.Radial flow reaction turbine
373. Highest useful compression ratio is the compression ratio at which
A. An engine can be safely operated
B. An engine gives maximum thermal efficiency
C. An engine operates smoothly
D. Detonation first becomes audible
E. None of the above
Answer: D.Detonation first becomes audible
374. The pour point of diesel fuel oil must be
A. More than the coldest atmospheric temperature at which oil is to be pumped
B. Less than 0?C
C. Less than the coldest atmospheric temperature of which oil is to be pumped
D. More than 100?C
E. More than 0?C
Answer: C.Less than the coldest atmospheric temperature of which oil is to be pumped
375. The emission of carbon monoxide in automobile exhaust will be low when the vehicle is
A. Cruising at low speeds
B. Idling
C. Decelerating
D. Cruising at high speeds
E. Accelerating
Answer: D.Cruising at high speeds
376. In a four stage compressor system first and third stage pressures are 1 and 9 kg/cm2 respectively. What will be the fourth stage delivery pressure
A. 243 kg/cm2
B. 81 kg/cm2
C. 3 kg/cm2
D. 27 kg/cm2
E. 9 kg/cm2
Answer: B.81 kg/cm2
377. In a lead cell battery the voltage per cell is
A. 6 volts
B. 1 volt
C. 1.5 volt
D. 2 volts
E. 1.1 volt
Answer: D.2 volts
378. Ignition quality of diesel fuel is expressed by
A. Octane number
B. Cetane number
C. Carbon percentage
D. Calorific value
E. None of the above
Answer: B.Cetane number
379. The use of Wilson’s line for flow calculation is associated with
A. Impulse turbines
B. Reaction turbines
C. Diesel engines
D. Steam-nozzles
E. Gas turbines
Answer: D.Steam-nozzles
380. Rateau turbine is a
A. Velocity compounded impulse turbine
B. Pressure compounded reaction turbine
C. Velocity compounded reaction turibine
D. Pressure compounded impulse turbine
E. Pressure-velocity compounded turbine
Answer: D.Pressure compounded impulse turbine
381. Centrifugal blowers can supply
A. Large volumes of air at low pressures
B. Large volumes of air at high pressures
C. Small volumes of air at high pressures
D. Small volumes of air at low pressures
E. None of the above
Answer: A.Large volumes of air at low pressures
382. To augment the thrust of jet propulsion units part of the fuel is burned in the exhaust. How does this fuel burn
A. Some chemicals rich in oxygen are mixed with fuel
B. Oxygen is also supplied along with fuel
C. 600;1
D. Fuel is never burned in exhaust pipe
E. Fuel finds oxygen from excess air supplied to engine
Answer: E.Fuel finds oxygen from excess air supplied to engine
383. Intake air filters are provided on air compressor for
A. Removing dirt and dust from suction air
B. Reducing temperature of suction air
C. Reducing pressure of suction pressure
D. Removing impurities of air
E. None of the above
Answer: A.Removing dirt and dust from suction air
384. Which one of the following factors will not assist in getting high power output from a compression ignition engine
A. High compression ratio
B. Fine atomisation of fuel
C. High charge density
D. Large quantity of excess air
E. None of the above
Answer: D.Large quantity of excess air
385. The lowest temperature upto which a mercury thermometer can be used is
A. ? 39?C
B. ? 260?C
C. ? 173?C
D. ? 10?C
E. 0?C
Answer: A.? 39?C
386. In case of a condensing turbine the pressure in the last stage of the turbine is
A. Same as atmospheric pressure
B. Slightly above the atmospheric pressure
C. 5 to 6 kg/cm2 above the atmospheric pressure
D. Less than the atmospheric pressure
E. 10 to 12 kg/cm2 above the atmospheric pressure
Answer: D.Less than the atmospheric pressure
387. The blades of a turbine are made of
A. High speed steel
B. Cast iron
C. Alloy steel
D. Nickel alloy
E. Stainless steel
Answer: D.Nickel alloy
388. The frictional horse power of a well adjusted petrol engine should be nearly
A. 50%
B. 40%
C. 25%
D. Carbon dioxide
E. 10%
Answer: E.10%
389. LPG stands for
A. Liquefied petroleum gas
B. Low pressure gas
C. Light pressure gas
D. Lubricated petroleum gas
E. None of the above
Answer: A.Liquefied petroleum gas
390. The term scavanging is generally associated with
A. High speed engines
B. Air cooled engines
C. Multi-cylinder engines
D. Two stroke engines
E. Vertical engines
Answer: D.Two stroke engines
391. Solubility of a gas in a liquid at small concentration is represented in
A. Henry’s law
B. Clausius Clapeyron equation
C. Raoult’s law
D. Dalton’s law
E. None of the above
Answer: A.Henry’s law
392. The engine provided on scooters is generally
A. Four stroke, air cooled
B. Four cylinder, air cooled
C. Two stroke, double acting
D. Two stroke, air cooled
E. Four stroke, water cooled
Answer: D.Two stroke, air cooled
393. The instrument used for the measurement of area of p-v diagram is known as
A. Digitometer
B. Clinometer
C. Planimeter
D. Areameter
E. Graphometer
Answer: C.Planimeter
394. If in a compression ignition engine the noise level is to be reduced, the design features which will not be affected are
A. Combustion system
B. Exhaust muffling
C. Intake muffling
D. Fuel injection equipment
E. None of the above
Answer: D.Fuel injection equipment
395. For dry saturated steam the value of adiabatic index n is taken as
A. 1.135
B. 1.41
C. 1.35
D. 25 to 30
E. 1.68
Answer: A.1.135
396. In a petrol engine the mixture strength for maximum power is
A. 1 ; 5
B. Carbon dioxide
C. 1 ; 30
D. 1 ; 23
E. 1 ; 13
Answer: E.1 ; 13
397. The main purpose of compounding in case of steam turbines is to
A. Reduced speed of rotor
B. Reduced exist losses
C. Improve thermal efficiency
D. All of the above
E. None of the above
Answer: D.All of the above
398. Which of the following is not the same as watt?
A. Joule/sec
B. Amperes/volt
C. Ampere x volt
D. (Ampere)2 x ohm
E. None of the above
Answer: B.Amperes/volt
399. In an engine radiator, heat is transferred by
A. Conduction
B. Convection
C. Radiation
D. Conduction and convection
E. None of the above
Answer: D.Conduction and convection
400. A rich mixture will have an air-fuel ratio
A. Less than chemically correct
B. More than chemically correct
C. Chemically correct
D. Any of the above
E. None of the above
Answer: A.Less than chemically correct
401. The self-ignition temperature of diesel oil as compared to petrol is
A. Higher
B. Varies considerably
C. Lower
D. Depends on other factors
E. Same
Answer: A.Higher
402. Rank of coal is based on
A. Fixed carbon and heating value
B. Ash content
C. Ash and moisture content
D. Size
E. None of the above
Answer: A.Fixed carbon and heating value
403. Piston rings are made of
A. Aluminium
B. Carbon steel
C. Alloy steel
D. Copper
E. Cast iron
Answer: E.Cast iron
404. This purpose of supercharging an engine is
A. To increase the power output of engine
B. To reduce specific fuel consumption
C. To reduce the noise of engine
D. To improve cooling of cylinders
E. None of the above
Answer: A.To increase the power output of engine
405. The lowest temperatures that can be measured by a gas thermometer using nitrogen is
A. ? 100?C
B. 0?C
C. ? 200?C
D. ? 10?C
E. ? 137?C
Answer: C.? 200?C
406. Gusset stays are provided in
A. Steam turbines
B. Steam condensers
C. Chimney
D. Boilers
E. Steam engines
Answer: D.Boilers
407. One kg of octane is burnt by four alternative processes given below. In which case the work available will be maximum?
A. When burnt in an open pan in atmosphere
B. When burnt in an internal combustion engine
C. When burnt in a fuel cell
D. When burnt in a reversible process
E. None of the above
Answer: D.When burnt in a reversible process
408. For superheated steam in a nozzle the critical pressure ratio is
A. 0.528
B. 0.546
C. 0.64
D. 0.577
E. 1
Answer: B.0.546
409. Dark, black smoke from diesel engines usually results when the engine is
A. Idling
B. Running at slow speeds
C. Running at full speed but under no load conditions
D. Running at full load and full speed
E. Running at light loads
Answer: D.Running at full load and full speed
410. A starting motor should have capacity to generate power equal to
A. IHP
B. IHP-BHP
C. BHP
D. Friction horse power at cranking r.p.m
E. Friction horse power
Answer: D.Friction horse power at cranking r.p.m
411. Water gas is a mixture of
A. CO2 and N2
B. CO and H2
C. SO2, CO2 and N2
D. N2 and H2
E. CO, CO2 and SO2
Answer: B.CO and H2
412. A jet engine has
A. Propeller in front
B. Propeller in back
C. One propeller in front and one propeller in back
D. No propeller
E. None of the above
Answer: D.No propeller
413. A Lenoir cycle has a top temperature in the cycle
A. More than that of Otto cycle
B. Equal to diesel cycle
C. Weight of engine
D. Between Otto and diesel cycles
E. Less than diesel cycle
Answer: D.Between Otto and diesel cycles
414. In isochronous governors the speed drop is
A. 50 percent
B. 75 percent
C. 10 percent
D. 20 percent
E. Zero
Answer: E.Zero
415. In a Diesel engine the duration between the time of injection and time of ignition is called
A. Explosion period
B. Delay period
C. Period of ignition
D. Pre-ignition period
E. Burning period
Answer: B.Delay period
416. All but one of the following possible steam generator test difficulties would cause the apparent performance to be poorer than it actually is. One item would make the performance look better than it really is. Identify the item
A. Steam flow meter reads low
B. Steam temperature gauge reads too high
C. HHV of fuel is determined incorrectly, being too high
D. Coad scales are inaccurate, reading high
E. None of the above
Answer: D.Coad scales are inaccurate, reading high
417. Resilience is the property of materials in which
A. Materials resist deformation
B. Materials spring back or recoil when pressure is removed
C. Materials are easily deformed
D. Materials can be easily pressed
E. None of the above
Answer: B.Materials spring back or recoil when pressure is removed
418. Thermie
A. Is quantity of heat required to raise temperature of one tonne of water from 14.5?C to 15.5?C
B. Is a unit of latent heat measurement
C. Is thermal conductivity of materials
D. Is a unit of temperature measurement
E. Is the temperature change in water when 1000 calories of heat are added to 1 gm of water, gradually
Answer: A.Is quantity of heat required to raise temperature of one tonne of water from 14.5?C to 15.5?C
419. Induced draft fan for a boiler is always located
A. Near the cooling tower
B. At the foot of the chimney
C. Near the coal hopper
D. Near the water treatment
E. On the top of the chimney
Answer: B.At the foot of the chimney
420. Intercooling in multistage compressors is done
A. To supply-air at two different pressures for use
B. To cool air during compression
C. To cool the air at delivery
D. To enable use of small cylinders and eliminate problems of unbalanced forces
E. To minimise the work of compression
Answer: E.To minimise the work of compression
421. Which of the following is an important consideration in the design of turbine blades?
A. Creep
B. Shape
C. Exhaust temperature
D. Air-fuel ratio
E. None of the above
Answer: A.Creep
422. Sensible heat is
A. That heat which causes change of state
B. That heat which produces a rise of temperature
C. That heat which produces a rise of temperature
D. That can only be sensed by a thermometer
E. None of the above
Answer: C.That heat which produces a rise of temperature
423. The effieincy of a diesel cycle increases with
A. increase in cut off
B. decrease in cut off
C. decrease in compression ratio
D. None of the above
E. Carbon dioxide
Answer: B.decrease in cut off
424. In a throttle governed steam engine
A. Admission pressure is reduced while cut off remains unaltered
B. Admission pressure remains constant while cut off is altered
C. Admission pressure and cut off both are altered
D. Admission pressure is varied while cut off remains unaltered
E. Neither admission pressure nor cut off is altered
Answer: D.Admission pressure is varied while cut off remains unaltered
425. For gas turbines compressors used are
A. Centrifugal type
B. Lobe type
C. Axial flow type
D. Sliding vane type
E. Reciprocating type
Answer: C.Axial flow type
426. How many kg of air will contain one kg of oxygen?
A. 6.65 kg
B. 10 kg
C. 4.35 kg
D. 12.5 kg
E. 1 kg
Answer: C.4.35 kg
427. Vapour lock is
A. Seizure of supply of fuel in a diesel engine
B. Serious restriction to the supply of fuel due to excessively rapid formation of vapour in S.I. engine
C. Locking of carbourettor jets due to vapour formation
D. Locking of jets due to impurities in petrol
E. None of the above
Answer: B.Serious restriction to the supply of fuel due to excessively rapid formation of vapour in S.I. engine
428. Which of the following part is not common between a steam engine and a petrol engine?
A. Crankshaft
B. Connecting road
C. Piston rings
D. Muffler
E. Piston
Answer: D.Muffler
429. The efficiency of a jet engine is higher at
A. Higher altitudes
B. Lower altitudes
C. High speeds
D. High speeds and low altitudes
E. Low speeds
Answer: A.Higher altitudes
430. Which of the following is a false stagement: The cause of excessive engine vibrations especially at high speeds in spark ignition engines is
A. Unequal distribution of mixture
B. Unbalanced crankshaft
C. Unequal compression of engine cylinders
D. Ignition distributor point not synchrohized
E. Unbalanced fan or loose fan blade
Answer: A.Unequal distribution of mixture
431. In regenerative feed heating system the steam ‘bled’ from turbine exchanges heat with
A. High pressure steam coming from boiler
B. Air for preheating
C. Fuel for preheating
D. Feed water for boiler
E. All of the above
Answer: D.Feed water for boiler
432. In thermodynamics spontaneous processes are those
A. Where a difference is observed in any microscopic property of the system between different times or states
B. Where a difference is observed in any microscopic property of the system between different times or states
C. Which occur in the direction of an intensive property or driving force contained within the system
D. Which require an agency outside the system to force the process
E. None of the above
Answer: C.Which occur in the direction of an intensive property or driving force contained within the system
433. Which one of the following is not a constituent of coal
A. Carbon
B. Manganese
C. Inorganic matter
D. Hydrogen
E. Nitrogen
Answer: B.Manganese
434. The gas used for cooling the conductors of large generators is
A. Nitrogen
B. Air
C. Oxygen
D. Carbon dioxide
E. Hydrogen
Answer: E.Hydrogen
435. During preliminary test run of an engine for 7 hours cycles if the engine stops after operating for 5 hours then
A. The engine is rejected
B. The engine is again run for 7 hours
C. The engine in run for balance 2 hours
D. The engine is removed and another piece tested
E. None of the above
Answer: B.The engine is again run for 7 hours
436. Prony brake is used for testing of
A. Slow speed engines
B. Large engines
C. Small engines
D. High speed engines
E. Engines having small flywheel
Answer: C.Small engines
437. The missing quantity in a steam engine can be reduced by all of the following methods EXCEPT
A. Superheating the steam supplied to the engine
B. Steam jacketing of cylinder walls
C. Reducing the speed of the engine
D. Dompounding the expansion of steam in two or more cylinders
E. 85% octane + 15% heptane
Answer: C.Reducing the speed of the engine
438. In the Bomb calorimeter the fuel to be tested is burned
A. There is no consideration of pressure, volume or temperature.
B. At constant temperature
C. At constant volume
D. In open atmosphere
E. At constant pressure
Answer: C.At constant volume
439. The maximum horse power of a 150 CC scooter engine is around
A. 3
B. 1.5
C. 15
D. 8
E. 33
Answer: D.8
440. Boilers using Bagasse as fuel use
A. Travelling grate stroker
B. Underfeed stokers
C. Pulverized fuel burners
D. Chain grate stokers
E. Spreader stokers
Answer: E.Spreader stokers
441. The enthalpy of vaporisation is minimum at
A. 100?C
B. Critical temperature
C. 0?C
D. 25 to 30
E. Absolute zero
Answer: B.Critical temperature
442. Which part of a gas turbine is subjected to the highest temperature?
A. Blades
B. Regenerator
C. Intercooler
D. Compressor coupling
E. Compressed air
Answer: A.Blades
443. In case of glass tube type water level indicator for a boiler
A. One end of the tube is connected to water space and the other is connected to steam space in the drum
B. Both ends of the tube are connected to water space
C. One end of the tube is connected to water space and the other end connected to chimney
D. One end of the tube is connected to water space and the other end is connected to superheated steam outlet from superheater
E. One end of the tube is connected to water space and the other is open to atmosphere
Answer: A.One end of the tube is connected to water space and the other is connected to steam space in the drum
444. Baffles are provided on engines to
A. Improve engine performance
B. Improve heat transfers rate
C. Guard against dirt and dust
D. Assist in starting the engine
E. Reduce fuel consumption
Answer: B.Improve heat transfers rate
445. A rope brake dynamometer falls under the category of
A. Transmission type dynamometer
B. Hydraulic dynamometer
C. Mechanical friction type dynamometer
D. Electrical type dynamometer
E. Torsion type dynamometer
Answer: C.Mechanical friction type dynamometer
446. Live storage of fuel means
A. Fuel stored to meet day’s requirement for the boiler
B. Fuel stored for supply at any time during emergency
C. Fuel stored at the plant
D. Fuel stored near the burners
E. None of the above
Answer: A.Fuel stored to meet day’s requirement for the boiler
447. In closed cooling system
A. Hot water is recirculated after cooling
B. Constant fresh water for cooling is supplied
C. Water surrounding the cylinder is allowed to evaporate
D. Air and water cooling is simultaneously used
E. Water does not flow
Answer: A.Hot water is recirculated after cooling
448. In a four stroke petrol engine
A. Intake valve closes before TDC
B. Intake valve closes after BDC
C. Exhaust valve closes before BDC
D. Exhaust valve open before BDC
E. None of the above
Answer: B.Intake valve closes after BDC
449. Coking is
A. In boiler furnace some coal becomes plastic and forms lumps or masses of coke
B. Making cakes of coal out of fine powders
C. Coal produced from burning of wood in inert atmosphere
D. Free burning coals are known as coking coals
E. None of the above
Answer: A.In boiler furnace some coal becomes plastic and forms lumps or masses of coke
450. Shock effect in the nozzle generally occurs in
A. Inlet
B. Converging section
C. Throat
D. Diverging section
E. Exit
Answer: D.Diverging section
451. Dehydration is the process of removal of
A. hydrogen from water
B. hydrogen from hydrocarbon
C. moisture from anything that is wet
D. hydrogen from alcohols
E. addition of water vapour to a substance
Answer: C.moisture from anything that is wet
452. For minimum work in multistage compression, the work done on
A. First stage should be least
B. Last stage should be least
C. All stage should be equal
D. There is no such consideration
E. None of the above
Answer: C.All stage should be equal
453. For the same maximum pressure and heat input the least efficient cycle is
A. Diesel cycle
B.
C. Otto cycle
D. Weight of engine
E. Brayton
Answer: C.Otto cycle
454. A Curtis turbine is
A. A velocity compounded readtion turbine
B. A pressure compounded reaction turbine
C. A pure reaction turbine
D. An impulse reaction turbine
E. None of the above
Answer: A.A velocity compounded readtion turbine
455. If the performance of diesel engines of different sizes, cylinder dimensions and horse power ratings are to be compared, which of the following parameter can be used for such comparison?
A. Air-fuel ratio
B. Brake specific fuel consumption
C. Volumetric efficiency
D. Swept volume
E. None of the above
Answer: B.Brake specific fuel consumption
456. For same heat input and same compression ratio
A. Otto cycle and Diesel cycle are equally efficient
B. Otto cycle is less efficient than Diesel cycle
C. Otto cycle is more efficient than Diesel cycle
D. Efficiency depends mainly on working substance
E. None of the above
Answer: C.Otto cycle is more efficient than Diesel cycle
457. The volumetric efficiency of a well adjusted engine at full load may be
A. 40 to 55 percent
B. 10 to 30 percent
C. 75 to 95 percent
D. 50 to 65 percent
E. 30 to 45 percent
Answer: C.75 to 95 percent
458. In Ambassador car, the engine is
A. Multi-cylinder type
B. V-type
C. Air cooled and reciprocating engines
D. Horizontal
E. Constant speed type
Answer: A.Multi-cylinder type
459. Dehydration means
A. Removing hydrogen from a mixture
B. Removing hydrogen from a hydrocarbon
C. Removing water from any matter
D. Removing hydrides from any matter
E. Any of the above
Answer: C.Removing water from any matter
460. Absolute pressure is
A. Gauge pressure
B. Gauge pressure + 1.03 kg/cm2
C. Gauge pressure-atmospheric pressure
D. Gauge pressure + atmospheric pressure
E. None of the above
Answer: D.Gauge pressure + atmospheric pressure
461. Samples of exhaust gases from following engines have been collected
A. Diesel engine
B. Gas engine
C. 600;1
D. Petrol engine
E. Jet propulsion unit
Answer: E.Jet propulsion unit
462. Normally the colour of exhaust from a petrol engine is
A. Reddish
B. Black
C. Yellowish
D. Bluish
E. Violet
Answer: D.Bluish
463. The boilers using lignite as fuel do not use
A. Horizontal burner, pulverized fuel
B. Travelling grate stoker
C. U-flame pulverized fuel burner
D. Speader stoker
E. Underfeed stoker
Answer: E.Underfeed stoker
464. Cetane number of diesel generally used in India is in the range
A. 55 to 65
B. 40 to 55
C. 20 to 25
D. 15 to 20
E. 10 to 15
Answer: B.40 to 55
465. Scavenging efficiency of a four stroke diesel engine is
A. In the range 80 to 95 percent
B. In the range 50 – 80 percent
C. Below 50 percent
D. Between 100% and 95%
E. None of the above
Answer: D.Between 100% and 95%
466. The bottom ring on the piston is known as
A. Oil ring
B. Scrapper ring
C. Compression ring
D. Groove ring
E. Any of the above
Answer: A.Oil ring
467. In a compression ignition engine squish is
A. Created at the beginning of suction stroke
B. Created at the end of suction stroke
C. Created during combustion
D. Created towards the end of compression stroke
E. None of the above
Answer: D.Created towards the end of compression stroke
468. Which locomotives has the highest unbalanced forces?
A. Electric locomotives
B. Steam locomotives
C. Carbon dioxide
D. Diesel locomotives
Answer: B.Steam locomotives
469. For the same power and same speed, the flywheel of a two stroke engine as compared to that of a four stroke engine will be
A. There is no correlation
B. Same size
C. Small
D. Bigger
E. Different shape
Answer: D.Bigger
470. The maximum amount of dissociation occurs in the burnt gases of a
A. Carbon dioxide
B. lean mixture
C. chernically correct mixture
D. rich fuel mixture
E. weak fuel mixture
Answer: C.chernically correct mixture
471. In a Carnot cycle the algebraic sum of the entropy changes for the cycle is
A. Zero
B. Either positive or negative
C. Negative
D. Depends on the properties of working substance
E. Positive
Answer: A.Zero
472. Blue smoke from a diesel engine indicates the presence of
A. Unburnt carbon
B. Unburnt oil
C. Carbon dioxide
D. Carbon monoxide
E. Nitrous oxide
Answer: B.Unburnt oil
473. A turbo-charger is used
A. In gas turbines for compression of air
B. For supercharging reciprocating engine
C. In jet propulsion units
D. In rockets for producing air fuel mixture
E. None of the above
Answer: B.For supercharging reciprocating engine
474. For same compression ratio and same heat input
A. Otto cycle is more efficient
B. Diesel cycle is more efficient
C. Both are equally efficient
E. None of the above
Answer: A.Otto cycle is more efficient
475. Which is the external loss in a steam turbine?
A. Blade friction losses
B. Nozzle losses
C. Disc friction losses
D. Back pressure losses
E. Gland leakage losses
Answer: D.Back pressure losses
476. If engines of different horse power, rpm, cylinder dimensions are to be compared for their performance, the parameter of comparison could be
A. Mean effective pressure
B. Specific speed
C. Exhaust temperature
D. Fuel consumption
E. Unit speed
Answer: A.Mean effective pressure
477. Ambassador car engine is
A. F-type
B. Overhead valve type
C. Side valve type
D. L-type
E. Overhead inlet and side exhaust type
Answer: B.Overhead valve type
478. Which of the following chemical acts as anti-freeze?
A. Naphtha
B. Glycol
C. Ethyl alcohol
D. Lead acetate
E. n-heptane
Answer: B.Glycol
479. A low pressure accumulator is generally used with which of the following turbine
A. Mixed pressure turbine
B. Back pressure turbine
C. Impulse turbine
D. Condensing turbine
E. Reaction turbine
Answer: A.Mixed pressure turbine
480. Which is not the cause for loss of heat in boiler due to incomplete combustion?
A. Under cooling of furnace at low ratings
B. Improper secting of boiler
C. Insufficient air supply
D. Boiler drum uninsulated
E. Fuel bend in proof condition
Answer: D.Boiler drum uninsulated
481. Temporary hardness of water is caused by
A. Bicarbonates of calcium and magnesium
B. Sulphates of calcium and magnesium
C. Chlorides of calcium and magnesium
D. Nitrates of calcium and magnesium
E. None of the above
Answer: A.Bicarbonates of calcium and magnesium
482. Crankcase explosion occurs in
A. Four stroke SI engines
B. Four stroke Cl engines
C. Two stroke Cl engines
D. Gas engines
E. Two stroke SI engines
Answer: E.Two stroke SI engines
483. Which of the following offers best resistance to knocking in S.I. engines?
A. Aromatics
B. Paraffins
C. Carbon dioxide
D. Naphthenes
E. Olefins
Answer: A.Aromatics
484. Which of the following engine can work on very lean mixture?
A. Petrol engine
B. Diesel engine
C. Two stroke engine
D. Wankel engine
E. Four stroke engine
Answer: B.Diesel engine
485. Overall thermal efficiency of a thermal power plant is
A. Carnot cycle efficiency
B. 50 to 70% of theoretical efficiency
C. Product of boiler efficiency, turbine efficiency and generator efficiency
D. Rankine cycle efficiency
E. None of the above
Answer: C.Product of boiler efficiency, turbine efficiency and generator efficiency
486. In gas and petrol engines thermal efficiency may be expected in the range
A. 50 percent
B. 30 to 35 percent
C. 10 – 15 percent
D. 15 to 25 percent
E. 60 percent
Answer: B.30 to 35 percent
487. A 200 MW generator should be cooled by
A. Nitrogen
B. Hydrogen peroxide
C. Hydrogen
D. Water
E. Air
Answer: C.Hydrogen
488. Which of the following exists as highest pressure in a diesel engine
A. Exhaust gases in silencer
B. Lubricating oil
C. Fuel at the time of injection
D. Air at the end of compression stroke
E. Air during suction
Answer: C.Fuel at the time of injection
489. A camshaft is not provided in case of
A. Two stroke engines
B. High speed engines
C. Multicylinder engines
D. ir cooled engines
E. Vertical engines
Answer: A.Two stroke engines
490. The compression ratio in case of a gas turbine is of the order of
A. 7
B. 12
C. 20
D. 5
E. 24
Answer: A.7
491. Corona is generally accompanied by a faint glow and
A. Spark
B. Sparking
C. Heating of conductors
D. Explosion
E. Hissing noise
Answer: E.Hissing noise
492. If after some use the lower part, electrodes and beathing space of a spark plug are found coated by deposits of soot and carbon, the conclusion will be
A. Spark plug is of proper heat rating
B. Spark advance is incorrect
C. Spark plug is short circuited
D. Composition of mixture in the engine is correct
E. Spark plug is of too high heat rating
Answer: E.Spark plug is of too high heat rating
493. As the compression ratio increases the volumetric efficiency of air compressor
A. Increases
B. Decreases
C. Does not change
D. Unpredictable
E. None of the above
Answer: B.Decreases
494. A fan is being used under certain conditions. If the fan speed is doubled the power requirement will be
A. 8 times
B. 16 times
C. Unchanged
D. Double of the original
E. Four times
Answer: A.8 times
495. A jet engine has
A. Propeller on top
B. No propeller
C. Propeller in back
D. Two propellers
E. Propeller in front
Answer: B.No propeller
496. In jet engines the compression ratio
A. Varies with altitude
B. Varies with square of speed
C. Varies as cube of speed
D. Remains constant
E. None of the above
Answer: B.Varies with square of speed
497. Steam trap is a device that
A. Allows passage of water but prevents the passage of steam
B. Allows passage of air but prevents passage of steam
C. Allows passage of the flue gases but prevents flow of steam
D. None of the above
E. Chain grate stokers
Answer: A.Allows passage of water but prevents the passage of steam