Category: Objective Questions

Molecular Biology Multiple Choice Questions on “Degradation of Proteins”.

1. How many types of protein degradation pathways are seen in a eukaryotic cell?
A. 1
B. 2
C. 3
D. 4

Answer: B
Explanation: Proteins are rapidly degraded in response to specific signals, providing another mechanism for the regulation of intracellular enzyme activity. In addition, faulty or damaged proteins are recognized and rapidly degraded within cells, thereby eliminating the consequences of mistakes made during protein synthesis. In eukaryotic cells, two major pathways – the Ubiquitin-proteasome pathway and lysosomal proteolysis – mediate protein degradation.

2. Ubiquitin degradation mechanism recognizes ____________
A. Cytosolic protein
B. Nuclear protein
C. Structural protein
D. Both cytosolic and nuclear proteins

Answer: D
Explanation: Ubiquitin degradation mechanism recognizes both cytosolic and nuclear proteins. The major pathway of selective protein degradation in eukaryotic cells uses Ubiquitin as a marker that targets both cytosolic and nuclear proteins for rapid proteolysis.

3. Ubiquitin has ___________ of amino acids.
A. 70
B. 75
C. 76
D. 72

Answer: C
Explanation: Ubiquitin is a 76 amino acid polypeptide. This is highly conserved in all eukaryotes (yeasts, animals and plants).

4. Ubiquitin binds to the ___________ amino acid residue for degradation.
A. Proline
B. Lysine
C. Serine
D. Valine

Answer: B
Explanation: Proteins are marked for degradation by the attachment of Ubiquitin to the amino group of the side chain of a lysine residue. Additional ubiquitins are then added to form a multiubiquitin chain.

5. The Ubiquitin-proteasome degradation pathway is an energy dependent process.
A. True
B. False

Answer: A
Explanation: Ubiquitin-proteasome degradation pathway is an energy independent process. Thus, both the attachment of ubiquitin and the degradation of marked proteins require energy in the form of ATP.

6. Which of the following is a Ubiquitin activating enzyme?
A. E1
B. E2
C. E3
D. E4

Answer: A
Explanation: Ubiquitinization is a multistep process. In this process, the first step is the activation of ubiquitin. This is done by the attachment of Ubiquitin activating enzyme, E1 to the ubiquitin.

7. The Ubiquitin-proteasome pathway is an active target for anticancer drugs.
A. True
B. False

Answer: A
Explanation: The ubiquitin-proteasome pathway is responsible for the degradation of several important regulatory proteins, including proteins that control cell proliferation and cell survival. Since the growth of cancer cells depends on the degradation of these regulatory proteins, the proteasome has emerged as a target for anti-cancer drugs.

8. Which of the following is the substrate specific enzyme of the following?
A. E1
B. E2
C. E3
D. E4

Answer: C
Explanation: Most cells contain a single E1 but have several E2s and al large number of E3 enzymes. Different E3s recognize different substrate proteins, and the specificity of these enzymes is what selectively targets cellular proteins for degradation by the ubiquitin-proteasome pathway.

9. The Cdk1 activates which of the following type of Ubiquitin enzymes?
A. E1
B. E2
C. E3
D. E4

Answer: C
Explanation: Cdk1 activates an ubiquitin ligase that targets cyclin B for degradation towards the end of mitosis. The E3 enzymes are known as the ubiquitin ligases that proceeds this step.

10. Ubiquitinization always leads to the degradation of the protein.
A. True
B. False

Answer: B
Explanation: Although polyubiquitin chains usually target proteins for degradation, the addition of ubiquitin to some proteins serves other functions. For example, the addition of single ubiquitin molecules to some proteins is involved in regulation of DNA repair, transcription and endocytosis.

11. Lysosomes does not have which one of the following properties?
A. Membrane bound organelle
B. Digestive enzymes
C. Cell metabolism
D. Carrier vesicles

Answer: D
Explanation: Lysosomes are membrane-enclosed organelles that contain an array of digestive enzymes, including several proteases. They have several roles in cell metabolism, including the digestion of extracellular proteins taken up by endocytosis as well as the turnover of cytoplasmic organelles and cytosolic proteins.

12. For the process of autophagy the formation of vesicles occurs. The membrane of these vesicles are derived from ___________
A. Nuclear membrane
B. Cell membrane
C. Mitochondria
D. Golgi membrane

Answer: C

Molecular Biology Multiple Choice Questions on “Many Plasmids Help their Host Cells”.

1. Where do the chimera molecules propagate?
A. Plasmid
B. Phagemid
C. Host
D. Carrier

Answer: C
Explanation: Chimera or recombinant molecules needs a host for replication and propagation. Thus host selection is very essential for the propagation of a certain recombinant molecule.

2. Mutation sometimes assists the uptake of DNA material. It is a transformational regulator.
A. True
B. False

Answer: A
Explanation: DeoR is a mutation that helps in the uptake of the DNA. This process is one of the transformational regulators and it also has a DNA binding activity.

3. What is the DNA sequence for cleavage by the endonuclease that is coded by hsdR?
A. AACGCNNTGC
B. AAGCCNNTGC
C. AGCCGNTTCC
D. ACGNNTGCTT

Answer: A
Explanation: hsdR encodes for a type I restriction endonuclease. This endonuclease is known to identify the methylated sequence AACGCNNTGC.

4. In which of the following methylation dependent restriction system is necessary?
A. Type III
B. Type II
C. Type I
D. mcrA

Answer: D
Explanation: Methylation dependent restriction enzymes are the products of mcrA, mcrB and mrr loci. It can degrade the sites that contain the methylated cytosine or adenine residue.

5. The DAM protein methylates which residue in the sequence GATC?
A. G
B. A
C. T
D. C

Answer: A
Explanation: The DAM protein is responsible for the methylation of the newly formed DNA strands. It is known to methylate the adenine residue in the sequence GATC.

6. The quality and yield of plasmid DNA preparation both are enhanced by end A mutation.
A. True
B. False

Answer: A
Explanation: The gene for DNA specific endonuclease is inactivated by the end A mutations. This mutation is sometimes induced in the host molecules which is seen to enhance both quality and yield of plasmid DNA.

7. What is the main characteristic that is present in a useful transformation method?
A. Property of plasmid
B. Ca²⁺ concentration
C. Efficiency of transformation
D. Availability of optimal physical conditions

Answer: C
Explanation: All transformation methods cannot be used equivalently if the participants are not efficient. Thus efficiency of the vector and its complementary host is the most important factor in case of transformation which determines the range of transformants produced.

8. Plasmids contribute to the survivality of its host cells.
A. True
B. False

Answer: A
Explanation: The genes contained in the plasmid are not of essential use for the bacterium for its day-to-day survival. Instead they help the bacterium to overcome stressed situations without which the bacterium may die.

9. Which of the following types of resistance is not provided by the plasmid for its host?
A. Antibiotic resistance
B. Heat resistance
C. Phage infection
D. Heavy metals

Answer: C
Explanation: Resistance to phage infection requires the production of nucleases which is provided by the bacterial genome itself and not the plasmid. The resistances such as antibiotic, temperature, metal, toxic etc are provided by the plasmid DNA.

10. The drug, quinolone, resistance is observed in which of the following?
A. Klebsiella pneumoniae
B. Bacillus thuringiensis
C. Streptococcus pneumoniae
D. Staphylococcus lentus

Answer: A
Explanation: Quinolone resistance gene is are frequently found on the plasmids that contain the ESBL genes. They provide resistance to substances such as aminoglycose, Qnr proteins etc. These resistances are provided in the plasmid containing bacterial family Enterobacteriaceae such as E. coli or Klebsiella pneumoniae.

11. Certain products produced by the plasmid genes can kill other microbes in its vicinity.
A. True
B. False

Answer: A

Energy Engineering Multiple Choice Questions on “Cooling Water System, Air & Fuel Gas System”.

1. What type of draught fan is used to draw air from the air heater?
A. Balanced draught fan
B. Induced draught fan
C. Forced draught fan
D. Artificial draught fan
View Answer

Answer: C
clarification: Forced draught fan is used to draw the air. This is installed near the base of boiler and air is forced to pass through the furnace, economizer and to the air stack. This is also called a positive draught system because pressure and air is forced to flow through the system.

2. In what form are the products of combustion in steam powered plant?
A. Air products
B. Flue gas
C. Slurry
D. Hot water

Answer: B
clarification: The products of combustion are in form of flue gas. Flue gas is the gas which is exiting to the atmosphere via a flue, which is channel for releasing exhaust gas from steam power plant. The flue gas is high in the contamination of nitrogen, oxygen and carbon dioxide. And also it contains a small amount of pollutants, such as soot and other types of oxides.

3. How flue gas is made use of in steam power plant?
A. To maintain the constant pressure inside boiler
B. To heat the water in the tubes of boiler
C. To increase or decrease the pressure inside the boiler
D. To remove all unnecessary chemical constituents

Answer: B
clarification: The flue gases are circulated in the furnace to heat the water in tubes. First it is passed over economizer and then to the pre-heater. And then finally after making maximum utilization of the flue gas they are exhausted through chimneys.

4. How is flue gas discharged through the chimneys?
A. By using induced draught fan
B. By using balanced draught fan
C. By using forced draught fan
D. By using mechanical draught fan
View Answer

Answer: A
clarification: After extracting maximum possible heat by circulating the flue gas in furnace. Induce draught fan is used to remove the left over gas via chimney. This is located near the base of the chimney. The air is sucked in by reducing the pressure below atmosphere. The draught produced is independent of temperature of hot gases.

5. What is the purpose of chimney?
A. To provide air ventilation
B. To eliminate noise produced in the system
C. To exhaust flue gases those is induced
D. To help in to suck the air required for system
View Answer

Answer: C
clarification: Chimneys are actually used to remove exhaust gases or products of combustion by using induced draught system. Almost all chimneys are constructed by bricks vertically and at a certain height in order easily release flue gases into atmosphere. The height of the chimneys shows its ability to transfer flue gases. The deposits of flue gas contaminations are made on the inner walls of the chimney.

6. What is the advantage of using flue gas inside a boiler?
A. Heats up boiler water tube quickly
B. Reduces the amount of amount of exhaust
C. Speeds of the process of boiler
D. Reduces the green house of effect

Answer: D
clarification: Using flue gas to heat up the water tubes reduces the greenhouse effect indirectly by making use of its heat to turn the water in water tubes into steam. This will be used in steam power plant to rotate the turbine and to produce electricity. And also plant operators can operate at best heat rate efficiency.

7. How is water pumped into condenser tubes in the steam power plant?
A. Water clarifier plant
B. Draught systems
C. Hydraulic capacity electric motor pump
D. Drawing through water

Answer: A
clarification: The water is pumped into condenser tubes through water clarifier plant. Clarifier helps in suspending solids from water in order to avoid damages to condenser tubes. Clarifiers are available in wide varieties of capacities of capacities and shapes depending on the steam plant.

8. When is the cooling tower preferred?
A. When there is plenty of water available
B. When there is scarcity of water
C. When the plant is of large capacity
D. When the amount of flue gas produced is very high

Answer: B
clarification: Cooling tower is preferred when there is scarcity of water. Instead of circulating the water directly, it is sprinkled in the cooling tower to condense the exhausted steam coming from the turbine. The loss of water due to evaporation is compensated by supplying water directly from the river.

9. What type of system is it, when the water is directly is used to condense the steam?
A. Closed system
B. Open system
C. Closed loop system
D. Open loop system

Answer: B
clarification: Water is pumped through the water clarifier plant and is used to circulate through the condenser in order to condense the steam coming out from the turbine. Water leaving the condenser is discharged to the downward side of the river. The amount of water in taken from river, the same amount of water is discharged back to river with the minimal temperature difference. And this following system is called open system.

10. How is the amount of cooling required by the steam power plant determined?
A. By the capacity of plant
B. By the amount of exhausted gas
C. By its thermal efficiency
D. By the type of fuel used (coal or uranium)

Answer: C
clarification: The amount of cooling required by the steam power plant is determined by its thermal efficiency. It has nothing to do whether it is fueled by coal or uranium; neither has it depended on the type of power plant (nuclear, thermal or hydel). Nuclear power plants have lower thermal efficiency than thermal plants. Higher the thermal plants lower the water usage for cooling.

11. How much amount of water does typical 1GWe plant uses for cooling per day?
A. 30 mega litre
B. 45 mega litre
C. 55 mega litre
D. 75 mega litre

Answer: D
clarification: Water is used in a plant to convert it into steam and utilize it for developing mechanical energy as well as it is used for the cooling of the steam produced. This water is supplied by the large water bodies like river or big lakes. The amount of utilized from water body is all discharged back at the end.

12. What type of system is it when the cooling tower is preferred?
A. Closed system
B. Open system
C. Closed loop system
D. Open loop system

Answer: A
clarification: When there is a scarcity of water a cooling tower is installed, such system is known as the closed system. In this system the condensed water is cooled by passing it through the cooling tower and water is sprinkled over steam. The loss of water due to evaporation is compensated by supply of water directly from the river.

13. What is the alternative cooling method for the thermal plant?
A. Wet cooling
B. Evaporation cooling
C. Dry cooling
D. Central air damping
View Answer

Answer: C
clarification: The alternative way of cooling method is dry cooling. Where in this method the heat is directly transferred to air via high flow forced drafts [industrial sized fans]. This is less efficient compared to wet cooling method since it uses very high amount of power to rotate the fans. Dry cooling method is very useful in the desert areas, where water scarcity is a huge problem.

14. How can we achieve high thermal efficiency in a power plant?
A. Drawing high output with limited input
B. Decreasing the working temperature
C. Increasing the working temperature
D. Maintain large temperature differential

Answer: D
clarification: The amount of heat discharged to environment depends on the plants thermal efficiency. High efficiency is achieved by having a large temperature differential. Irrespective of whether it comes from high internal heat or low temperature external environment, or both. The thermal efficiency of today’s nuclear power plant is around 35% whereas hotter coal burners can reach 40% or more. At last higher thermal efficiency is required to lower the water usage.

Energy Engineering Multiple Choice Questions on “Pulverised Mills – 1”.

1. How is coal pulverized in the ball mill?
A. By rotating the cylinder
B. By rolling the cylinder
C. By hammering the cylinder
D. By jolting the cylinder

Answer: A
clarification: The pulverization in ball mill takes place as a result of action between the balls and coal, as the cylinder they are put in is made to rotate. The cylinder is partly filled with various sized steel balls. The cylinder is rotated at a velocity of 130 m/min periphery.

2. Why pre-heater air and the tempered air are introduced in the pulverizer of ball mill?
A. To carry the ash out
B. To increase the combustion rate
C. To carry pulverized coal
D. To dry the coal by removing the moisture

Answer: C
clarification: A mixture of tempering air and hot air from pre-heater is introduced in the pulverizer. These streams of air carry the pulverized coal and pass through the classifier. The over-sized particles are thrown out of the air stream in the classifier and fine material is passed to the burner through exhaust fan.

3. The output of the mill can be controlled by the _________ located in the exhaust fan inlet duct.
A. Dampers
B. Blowers
C. Air duct
D. Ventilator’s

Answer: A
clarification: The output of the mill can be controlled by the dampers located in the exhaust fan inlet duct. These dampers vary the flow of air through the mill, thus controlling the rate of fuel removed from the mill. The dampers are operated by the boilers automatic combustion control.

4. Feeder output in cylinder of a ball mill is regulated on the basis of?
A. Cylinder capacity
B. No of balls
C. Level of coal
D. Rotation speed of cylinder

Answer: C
clarification: The feeder output is regulated by the coal level in the cylinder. When coal level in the cylinder attains sufficient height to seal off the lower channel than the differential control operates to stop the coal feed.

5. What is the pulverization capacity of the ball mill?
A. 10 tons of coal per hour
B. 20 tons of coal per hour
C. 50 tons of coal per hour
D. 80 tons of coal per hour

Answer: A
clarification: A ball has the capacity of pulverizing 10 tons of coal per hour containing 4% of moisture requires 28 tons of steel balls and consumes 20 to 25 KW hr energy per ton of coal. A wide range of fuels including anthracite and bituminous coal which are difficult pulverize, can still be used.

6. Why ball and race mill is also called as contact mill?
A. Because of rolling action between the balls and races
B. Because of ramming action between balls and races
C. Because of swirling action of balls and races
D. Because of mixture of balls and races
View Answer

Answer: A
clarification: The pulverization or crushing action in ball and race mill takes between the two moving surfaces called balls and races. The rolling action happens between these two. Then the coal passes between the rotating elements time and again until it has been pulverized to the desired degree of fineness.

7. The pulverization is completed by a combination of crushing impact and _______ between grinding surfaces.
A. Accretion
B. Erosion
C. Attrition
D. Dissolution

Answer: C
clarification: The pulverization is completed by a combination of crushing impact and attrition between grinding surfaces. The coal is crushed between two moving surfaces: balls and races. The upper stationary race and lower rotating race is driven by a worm and gear, hold the balls between them.

8. What type of feeder is used to supply the coal in ball and race mill?
A. Ring main feeder
B. Parallel feeder
C. Radial feeder
D. Rotating table feeder

Answer: D
clarification: The coal is supplied through the rotating table feeder at the upper right to fall on the inner side of the races. The moving balls and races trap coal between them to crush it to powder. Spring holds down the upper stationary race and adjusts the force needed for crushing.

9. Which type of fan is used in the ball and race mill?
A. Forced draught fan
B. Balanced draught fan
C. Artificial draught fan
D. Natural draught fan
View Answer

Answer: A
clarification: A forced draught fan is used to supply hot air to the mill through the annular space surrounding the races. The air picks up the coal dust as it flows between the balls and races and then enters into the classifier above it.

10. What is the purpose of fixed vanes in the ball and race mill?
A. Forms a cyclonic flow
B. For easy movement of the coal
C. For directing the airflow
D. For barring the exhaust air to enter back into mill

Answer: A
clarification: The fixed vanes make the entering air to form a cyclonic flow throwing the oversized particles to the walls of classifier. The oversized particles slide down for further grinding in the mill. The coal particles of required size are taken to the burners with air from the top of the cylinder.

11. Why are heavy impurities provided in the process of ball and race mill?
A. To resist upward thrust caused by secondary air stream
B. To resist downward thrust caused by primary air stream
C. To resist upward thrust caused by primary air stream
D. To resist downward thrust caused by secondary air stream

Answer: C
clarification: The mill is provided with a means of separating heavy impurities from the coal and thus reducing wear and possible damage to the grinding element. These heavy particles resist the upward thrust caused by the primary air stream and collect in a compartment in the base of mill, and then they are removed periodically.

12. What is done when there is requirement for more coal in the ball and race mill?
A. The primary air flow is increased
B. The combustion intensity is reduced
C. The secondary air flow sucks out the light coal particles
D. The hopper is fully opened

Answer: A
clarification: When there is requirement for more coal, the primary air flow is increased automatically and its higher velocity in the mill carries additional coal in the furnace. This action reduces the amount of coal in the pulverizer and decreases the pressure drop, causing the feeder controller to supply more coal.

13. What happens due to the pressure in the pulverizer?
A. Pulverized fuel is blown into boiler room
B. Increases the rate of combustion
C. Makes the process is vigorous
D. The large particles in the pulverized fuels are removed out
View Answer

Answer: A
clarification: As the casing of the pulverizer is under pressure, the leakage of fine coal through the mill casing causes the pulverized fuel to be blown out into the boiler room. The fan used with this mill handles only air therefore the blades erosion by coal particle is eliminated.

14. What is the main disadvantage of race and ball mill pulverizer?
A. Mill requires extra floor area
B. It is directly connected to the motor
C. High power consumption
D. Greater wear

Answer: D
clarification: Ball and race mill have greater wear compared to other pulverizers. The advantages of lower space occupied, lower power consumption in kW hr/ton of coal pulverized, lower weight and lower capital cost have outweighed the wear problem and these pulverizers found general acceptance.

Energy Engineering Multiple Choice Questions on “Cooling Ponds and Towers”.

1. Open cooling system is also called as ____________
A. parallel system
B. once through system
C. air based system
D. non-reversible system

Answer: B
clarification: Open system is also called as once through system, in this system the water is drawn directly from the upstream side of the river pumped through the condenser and discharged to the downstream side of the river at temperature 5 to 10°C in excess of inlet temperature.

2. How many number of spray nozzle does each module on spray pond cooling system contains?
A. 1
B. 2
C. 3
D. 4
View Answer

Answer: D
clarification: Modules in spray pond cooling system contain 4 spray nozzles. The surface area of contact of water is increased when it is sprayed in air. Cooling occurs due to the evaporation of water vapours as the spray propels upwards and falls down to the surface.

3. Which of the following is the simplest method of cooling the condenser water?
A. Spray cooling pond
B. Cooling tower
C. Indirect air cooling
D. Hyperbolic cooling tower

Answer: A
clarification: Spray cooling pond is the simplest method of all. The hot water coming out of the condenser is sprayed through the nozzles to expose maximum surface area of water to air for effective cooling. The spray ponds are surrounded with wooden walls to prevent the wind from carrying the water particles.

4. In which type of cooling pond system are nozzles arranged on same elevation?
A. Single deck system
B. Double deck system
C. Natural Flow system
D. Direct flow system

Answer: A
clarification: In a single deck system spray nozzles are arranged at the same elevation. Its effective cooling effect is less than double deck system. Hot water is sprayed through the spray nozzle in air. Cooling occurs due to the evaporation of water vapors at the spray propels and falls down the surface.

5. In which type of cooling system are nozzles arranged on different elevation?
A. Single deck system
B. Double deck system
C. Natural Flow system
D. Direct flow system

Answer: B
clarification: In double system of cooling ponds the spray nozzles are arranged at different elevations. Cooling effect is more than single deck cooling system as water comes in contact with air at lower temperatures.

6. What are used in the direct flow system to transverse the pond before uniting at intake?
A. Separators
B. Filters
C. Baffle walls
D. Porous pipes

Answer: C
clarification: In direct flow system the hot water coming out of the condenser enters the middle channel. On reaching the far end it is divided into two currents being directed by the baffle walls so as to transverse the pond several times before uniting at intake point.

7. Select the disadvantage of cooling pond out of the given?
A. The area required of cooling in a cooling pond is small
B. Spray losses due to evaporation and windage run high
C. There is no control over the temperature of cooled water
D. The cooling efficiency is low compared with cooling water

Answer: C
clarification: The cooling effect is reduced with the decrease in wind velocity and if the load on the plant increases, the pond does not respond to the requirement. When the maximum cooling is required during increased load, it provides minimum cooling in absence of wind flow.

8. What type of cooling system is used in the large power plants?
A. Cooling ponds
B. Natural flow system
C. Cooling towers
D. Single deck system

Answer: C
clarification: In large power plants cooling towers are used in the place of cooling ponds. A cooling tower is a wooden or metallic rectangular structure, with packed baffling devices. The hot water is delivered to the top of tower and is made to fall down the tower and is broken into small particles while passing over the baffling devices.

9. How does outside air enter into the wet cooling system?
A. Air vents
B. Louvers
C. Tuyeres
D. Vacuum
View Answer

Answer: B
clarification: Air and water are thoroughly mixed by fill as water splashes down from one fill level to the next due to gravity outside air enters the tower through louvers from the side of the tower. The heat and mass transfer between water and air is enhanced due to intimate mixing.

10. How is water circulated throughout the dry cooling tower system?
A. Finned tubes
B. Metal pipes
C. Porous tubes
D. Swirling tubes

Answer: A
clarification: In dry cooling tower circulating water is passed through finned tubes over which cooling air is passed. Heat is rejected to air in the form of sensible heat. A dry cooling tower may be either natural draft type or forced draft type. These types are cheap than wet types of cooling tower.

11. Why is exhaust steam coming out of turbine is admitted to a steam header?
A. To increase the pressure
B. To decrease the velocity
C. To decrease the pressure drop
D. To control the pollution

Answer: C
clarification: Exhaust steam from turbine is admitted to a steam header in order to minimize the pressure drop. Steam gets condensed as it passes down through the finned tubes arranged in parallel rows.

12. In which system is Cooling of hot water is done on tray as step by?
A. Mechanical draught cooling system
B. Hyperbolic cooling tower
C. Atmospheric cooling tower
D. Wet cooling tower

Answer: C
clarification: In atmospheric cooling tower, the hot water is delivered at the top most trays and it falls down from one tray to another until it reaches the tank below the tower. The water is cooled by air flowing across the tower.

13. How does the flow of air occur in natural draught cooling towers?
A. Natural pressure head density between cold outside air and humid inside air
B. Variation in pressure of both cold outside air and humid inside air
C. Due to the given air vents and vacuum ports
D. Because of difference in the volume of both the of airs
View Answer

Answer: A
clarification: In natural draught cooling tower, the flow of air occurs due to the natural pressure head caused by density difference between the cold outside air and hot humid air inside. The disadvantage of natural draught cooling system is that, to produce to produce large draught the tower should be very high.

14. How is air produced in mechanical draught cooling tower?
A. Air Tuyeres
B. Propeller fans
C. Air blowers
D. Louvre

Answer: B
clarification: In mechanical draught cooling tower the draught of air id produced mechanically by means of propeller fans. This increases the cooling rate by increasing the air velocity over the wet surfaces and through the tower. These two towers give higher efficiency; reduce spray and windage losses and less ground area.

15. Why is induced draught considered better than the forced draught?
A. Because power requirement is high for forced draught
B. Maintenance of induced draught fan is costlier
C. Forced draught is less efficient
D. Forced draught produces less amount of speed of air
View Answer

Answer: A
clarification: Induced draught is considered to be better than forced draught because, the power requirement is high for forced draught and the maintenance of fan is costlier. The induced draught occupies less space ass the fan drives are placed at the top of the tower, the cooling effect is distributed across the entire cross section of the tower.

Energy Engineering Multiple Choice Questions on “Atomic Structure”.

1. Why has nuclear energy become an inevitable option for the development of the country?
A. Because less pollution caused by nuclear plant
B. High efficiency of nuclear energy
C. Due to acute shortage of other sources of energy
D. High cost of energy production of other sources

Answer: C
clarification: With the acute shortage of other sources of energy viz. fossil based fuels and hydel sources the use of nuclear energy has become an inevitable option for the both developed and developing country.

2. How much amount of nuclear energy burnt is equivalent to the energy produced by 3000 tonnes of coal?
A. 1kg
B. 5kg
C. 15kg
D. 20kg

Answer: A
clarification: The amount of heat generated by burning one kg of nuclear fuel is equivalent to the energy generated by burning 3000 tonnes of coal or 1600 tonnes of oil. The production of Nuclear energy is carried out by two methods which are nuclear fission and nuclear fusion.

3. What is the most attractive part of nuclear energy?
A. Supports countries development
B. Causes no pollution
C. Has high efficiency of energy production
D. Is available in abundance

Answer: B
clarification: Most attractive part of nuclear energy is that it has no combustion products and under safe working conditions contributes no pollutant to air. Site selection is completely independent of geographical area.

4. Nucleus consists of two sub-particles known as?
A. Nucleotides
B. Nucleons
C. Neutrons
D. Nucleosides
View Answer

Answer: B
clarification: Atom consists of a relatively heavy, positively charged nucleus and a number of much lighter negatively charged electrons. Electrons exist in various orbits around the nucleus. The nucleus consists of two sub-particles known as nucleons.

5. The atom as a whole is electrically charged.
A. True
B. False
View Answer

Answer: B
clarification: The atom as a whole is not electrically charged it is actually electrically neutral in its state. The electric charge on the proton is equal in magnitude but opposite in sign to that of electron, the number of protons is equal to the number of electrons in the orbit.

6. On which law is the nuclear energy explained?
A. Einstein’s law
B. Newton’s law
C. Rutherford law
D. Mendeleev law

Answer: A
clarification: The nuclear energy is explained the basis of Einstein’s law, one atom may be transformed into another by losing or acquiring some of the above sub-particles. This results in mass change Δm and enormous amount of energy is released (or absorbed). According to Einstein’s law,
ΔE = Δmc²
Where, c=light of speed.

7. Identify the element by its Atomic structure.

A. Helium
B. Hydrogen
C. Carbon
D. Oxygen

Answer: B
Explanation:

Most of the mass of the atom is in nucleus. The red dot is a proton it has positive charge of 1 unit, and black one is an electron, which has a negative charge of -1. There is only one orbital for hydrogen.

8. Identify the element by its atomic structure?

A. Hydrogen
B. Helium
C. Carbon
D. Oxygen
View Answer

Answer: B
Explanation:

The masses of three atomic sub-particles are,
Neutron mass, m_n = 1.008665 amu
Proton mass, m_p = 1.007277 amu
Electron mass, m_e = 0.0005486 amu.

9. Number of protons in the nucleus is called ___________
A. Atomic number
B. Mass number
C. Electric charge
D. Periodic number
View Answer

Answer: A
clarification: Number of protons in the nucleus is called atomic number Z. it is unique for each chemical element, and represents both the number of positive charges on the central massive nucleus of the atom and the number of electrons in orbits around the nucleus.

10. The total number of nucleons in the nucleus is called _________
A. Atomic number
B. Mass number
C. Electric charge
D. Periodic number

Answer: B
clarification: The total number of nucleons in the nucleus is called the mass number A. Nuclear symbols are written as _zX^A Where X is chemical symbol. The masses of atoms are compared on a scale in which an isotope of ₆C¹² has a mass of exactly 12.

11. To disrupt a nucleus and separate in into its component nucleons, energy must be supplied from outside and this energy is called?
A. Bonding energy
B. Kinetic energy
C. Binding energy
D. Nuclear energy

Answer: C
clarification: To disrupt a nucleus and separate in into its component nucleons, energy must be supplied from outside and this energy is called Binding energy. The nuclear force acts only when the nucleons are very close to each other and binds them into compact stable structure.

12. The net neutrons produced per initial neutron accounting for all possible losses is called?
A. Bombardment
B. Half life
C. Multiplication factors
D. Covalent bond
View Answer

Answer: C
clarification: The net neutrons produced per initial neutron accounting for all possible losses is called multiplication factor (K). If: K < 1 = system is subcritical.
K = 1 = System is critical.
K > 1 = system is super critical.

13. What is the time during which one half of a number of radioactive species decays or one half of their activity ceases?
A. Half Life
B. Super critical state
C. Semi life
D. Critical life

Answer: A
clarification: Half life is the time during which one half of a number of radioactive species decays or one half of their activity ceases. It is also used to characterize any type of exponential and Non-exponential decay.

14. Electrons that orbit outermost shell of an atom are called?
A. Valence electrons
B. Electrons
C. Electron Coefficients
D. Neutrons

Answer: A
clarification: Electrons that orbit outermost shell of an atom are called Valence electrons. The outermost shell is called valence shell. The presence of valence electron can determine the element’s chemical properties.

15. A covalent bond is also called as ____________
A. Atomic bond
B. Metal bond
C. Molecular bond
D. Metal bond

Answer: C
clarification: A covalent bond is also called as molecular bond, which involves sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, when these share an electron than it is called as covalent bonding.