# 200+ Power Plant Engineering (PPE) Solved MCQs

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1.

## Rankine cycle efficiency of a good Steam

A. 15 to 20%
B. 35 to 45%
C. 70 to 80%
D. 90 to 95%
Explanation: efficiency of rankine cycle in actual working condition is found to be between 35 to 45%.
2.

## A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature of 350°C and the Condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle?

A. 7.7
B. 17.7
C. 27.7
D. 37.7
Explanation: fixing the states; h1 = 340.5 kj/kg, h2 = h1 + v1 (p2 – p1) = 343.5 kj/kg, h3 = 3115.3 kj/kg, s3 = 6.7428 kj/kg – k, x4
3.

## On what basis are fire and water tube boilers are classified?

A. depending the combustion products formed
B. depending the state of fuel
C. depending on the steam formation rate
D. depending tubular heating surface
Answer» D. depending tubular heating surface
Explanation: based on the contents of the tubular heating surface, boilers are primarily classified as fire tube boiler and water tube boiler. fire tube boilers those in which production of combustion pass through the tubes and water tube boilers are those in which the products of combustion surround the water tubes from outside.
4.

## Cornish boiler is an example of which type of boiler?

A. fire tube boiler
B. water tube boiler
C. vertical tube boiler
D. externally fired boiler
Explanation: cornish boiler is an example of fire tube boiler and also includes cochran, lancashire, and locomotive and scotch marine boilers. fire tube boilers are those in which the products of combustion pass through the tubes and water lies around the outside of tubes. these boilers operate at moderate pressure (16-20bar) and more suitable to generate 3-8 tons of steam per hour which is used in process heating.
5.

## Stirling boiler is an example of which type of boiler?

A. inclined tube boilers
B. mobile boiler
C. fire tube boiler
D. water tube boiler
Explanation: water tube boilers are those in which the products of combustion (hot flue gas) surround the water tubes from outside. cold water enters the tubes and leaves hot. these boilers operate at very high pressures and are used for power generation.
6.

## Which of these is a stationary boiler?

A. locomotive boiler
B. marine boiler
C. mobile boiler
D. babcock-wilcox boiler
Explanation: if the boilers are used at one place only they are termed as stationary boilers. these boilers are used for either process heating in industries or for power generation in steam power plants. these are used at central station utility power plants, for plant process etc. ex: babcock-wilcox boiler, fluidized bed combustion (fbc) boiler.
7.

## Which of these is a mobile boiler?

A. lancashire boiler
B. stirling boiler
C. locomotive boiler
D. cochran boiler
Explanation: the boilers, if they are portable, i.e., if they can be moved from one place to other place those are known as mobile boilers. such boilers are used in locomotives and ships to get the engine moving. and also small units are used for temporary at working sites. ex: locomotive boiler, marine boiler etc.
8.

## Are boilers defined on the basis of heat source.

A. yes
B. no
Explanation: boilers can be classified based on fuel used for combustion or heat generation source. various heat sources are: heat generated by the combustion of fuel in solid, liquid or gaseous form. heat generated by hot waste gases as byproducts of other chemical processes. heat generated by electrical energy and nuclear energy.
9.

## What is the steam pressure limit of natural circulation boilers?

A. 650bar
B. 180bar
C. 400bar
D. 550bar
Explanation: water is purely circulated by density difference with most of the heat from the fuel flame being radiated to the water walls directly. the steam pressure of such boilers is limited to about 180bar, with water and steam being separated in the boiler drum.
10.

## Which of the given boilers operate above critical pressure?

A. natural circulation boilers
B. forced circulation boilers
C. once-through boilers
D. water tube boilers
Explanation: once-through boilers operate above critical pressure i.e., above 221.2bar. as the density of water and steam are same above the critical pressure there will be no recirculation. these types of boilers are also called as positive forced circulation boilers.
11.

## Which type of boilers are called drum-less boilers?

A. natural circulation boilers
B. fire tube boilers
C. positive forced circulation boiler
D. forced circulation boiler
Answer» C. positive forced circulation boiler
Explanation: in positive forced boilers, water enters the bottom of the tubes and completely transforms into steam as it passes through the tubes and reaches at the top. thus, these boilers do not need a steam drum and hence often referred as drum-less boilers. these boilers work at very high pressures.
12.

## Chances of sediments depositing inside the water tubes in the shell is less due to?

A. low working pressure
B. natural circulation of water
C. partial circulation of water
D. high working pressure
Explanation: due to high working pressure and positive circulation of water, chances of sediments depositing inside water tubes in the shell is less. this high working pressure of boiler in the shell can withstand high temperature or thermal stresses.
13.

## Out of the given option choose the advantage that supports fire tube boilers?

A. water circulation is cyclic
B. used as a mobile boiler
C. water circulation is limited inside boiler shell
D. bursting of flue tube does not cause any explosion
Answer» C. water circulation is limited inside boiler shell
Explanation: water circulation is limited inside the boiler shell. water need not be that much pure and needs minimum treatment like passing through a pressure filter. cleaning
14.

## Apart from feedheating, what should a plant have to obtain a gain in thermal efficiency?

A. lubrication
B. differential heating
C. reheating cycles
D. regenerative cycles
Explanation: to obtain a gain in thermal cycle efficiency, apart from the feedheating, there should be multiple number of reheats.
15.

## Which of the following needs to be incorporated to prevent the low pressure turbine exhaust wetness from being excessive?

A. double regeneration
B. double carnotization
C. double reheat
D. double cooling
Explanation: incorporating double reheat is one way to prevent the low pressure turbine exhaust wetness from being excessive.
16.

## What is the critical point of steam generation in a “once through” boiler?

A. 221.5 bar
B. 221.4 bar
C. 221.3 bar
D. 221.2 bar
Explanation: steam generation in a “once through” boiler is at the critical point of 221.2 bar.
17.

## In a typical layout of a 215MW reheat power plant, the feed in the boiler is at?

Explanation: in a typical layout of a 215mw
18.

## The input to the low pressure feedwater heater is from?

A. drain heater
B. drain cooler
C. drain pipe
D. none of the mentioned
Explanation: the input to the low pressure feedwater heater comes from the drain cooler which goes to the deaerator.
19.

## The best capable alternative source which can meet the future energy demand is

A. thermal power plant
B. nuclear power plant
C. hydroelectric power plant
D. geothermal power plant
Explanation: demand of electrical energy is increasing at fast rate owing to booming increase in the population and industrial growth. the reserves of fossil fuel i.e., coal, oil and gas are fast depleting. there are many alternative sources of energy but they are not enough to supply such huge demand, only
20.

## How much coal is required to generate energy equivalent to the energy generated by 1 kg of uranium?

A. 30000 tonnes of high grade coal
B. 300 tonnes of high grade coal
C. 10000 tonnes of high grade coal
D. 3000 tonnes of high grade coal
Explanation: one of the main attention for nuclear fuel is the huge amount of energy that can be released from a small quantity of active nuclear fuel. the energy obtainable by
21.

## Nuclear fuel in reactor lasts for

A. more than 5 months
B. few weeks
C. few days
D. more than 5 years
Answer» D. more than 5 years
Explanation: very small amount of nuclear fuel can produce very high amount of energy. nuclear fuel may remain in a reactor for more than 5 years.
22.

## Cost of nuclear fuel in nuclear power plant economics is considered as

A. running cost
B. maintenance cost
C. capital cost
D. development cost
Explanation: nuclear fuel in a nuclear reactor may remain for more than 5 years. so the cost of fuel injected initially is taken as capital cost and may be a few crore rupees.
23.

## Which of the following are not taken as operation and maintenance cost in economics of nuclear power plant?

A. taxes and insurance
B. salaries and wages of staff
C. cost of waste disposal
D. cost of processing materials
Explanation: taxes and insurance are taken as fixed costs. salaries and wages of operation and maintenance staff, cost of waste disposal and cost of processing materials are the operation and maintenance cost.
24.

## What is the overall efficiency of nuclear power plant?

A. 20 to 25%
B. 25 to 30%
C. 30 to 40 %
D. 50 to 70 %
Answer» C. 30 to 40 %
Explanation: the overall efficiency of a nuclear power plant is around 30 to 40%. efficiency is higher at high road factors. therefore, a nuclear power plant is always operated as a base load plant.
25.

## The land area required for installation of nuclear power plant is

A. more than thermal power plant
B. less than thermal power plant
C. equel to thermal power plant
D. depends on type of construction
Answer» C. equel to thermal power plant
Explanation: nuclear power plants need less area as compared to any other plant of same generation capacity. a 2000mw nuclear power plant needs about 80 acres whereas the coal fired steam power plant of same generation capacity needs 250 acres of land.
26.

## All of the nuclear fuel reserve will be ended in about 400 years.

A. true
B. false
Explanation: there are larger deposits of nuclear fuel available all over the world. therefore, such plants can ensure continued supply of electrical energy for thousands of years.
27.

## With respect to the load centre which location is suitable for stablishment of nuclear power plant?

B. near load centre but at reasonable distance
C. far away from load centre
D. near chemical industries
Explanation: these plants can be located near the load centre because of the negligible
28.

## Operating cost of nuclear power plant is less than thermal power plant.

A. true
B. false
Explanation: cost of fuel in nuclear power plant is taken as the capital cost. the the total operating cost involves wages and the salaries of operating and maintenance staff only, cost of disposal of waste etc.. the cost of transport and handling of coal for conventional thermal power plant is much higher than the cost of nuclear fuel.
29.

## What is the role of breaker house in coal feeding?

A. to break the coal into smaller pieces
B. to separate different sizes of coal
C. to separate the light dust from the coal
D. to powder the coal
Answer» C. to separate the light dust from the coal
Explanation: because of the brittle nature of the coal, it is a common nature of coal to emit light dust/coal dust during transportation, mining and machine handling. this dust needs to be cleared out and it is performed by coal breaker.
30.

## Large amount of coal is transported by

A. railway
B. sea or river ways
D. by airlifting
Explanation: the railway is preferred since it is quite economical as well as loading and unloading of coal is easy. and at stretch tons of coal can be transported by goods train from one place to another place. coal is considered as a bulk commodity value which falls in category of minerals and ores. if roadways
31.

## The coal is fed to the furnace through

A. conveyor belt
B. wagon tipper
C. hopper
D. crane
Explanation: hopper is the conical shaped slow coal dispenser to the furnace. it is placed right above the furnace and a live feeder mechanism is set at end of hopper for a controlled flow. there is no requirement of any external power/force since this works on gravity force.
32.

## What is the function of cyclone separators in pneumatic ash handling system?

A. to separate the lighter dust particles
B. to force up the movement of ash through pipes or tubes
C. to draw out the dust from furnace
D. to separate minute coal particles
Answer» A. to separate the lighter dust particles
Explanation: cyclone separators use air to swirl around the ash that has been dispensed into them. due to centrifugal action heavier ash settles down, where as lighter dust/ash particles is collected in hopper and dumped out. the air flows in helical pattern which makes easy for the heavier dust particle to settle down easily without interrupting the airflow.
33.

## Which medium is used to carry ash in the pneumatic ash handling system?

A. conveyor belt
B. water trough
C. air
D. chain belt
Explanation: in pneumatic ash handling system, air is used to carry ash to long distance at a capacity of 5 to 30 tonnes per hour. and the air used for this purpose is easily cleanable and can be exhausted back into atmosphere after the complete filtration processes.
34.

## Which system is noisy out of all the following ash handling systems?

A. steam jet ash handling system
B. mechanical ash handling system
C. pneumatic ash handling system
D. hydraulic ash handling system
Answer» C. pneumatic ash handling system
Explanation: the air is made to pass at very high pressure in order to carry out the ash for long distance. since the air is moving at high speed at high velocity in the conveying pipes, it tends to create a lot of noise by hitting the walls of pipe at swift turns and curves.
35.

## Which medium is used to carry ash in hydraulic system?

A. air
B. water
C. steam
D. conveyor
Explanation: water is used as the medium to carry ash at high velocity. depending on water pressure the system is divided as low pressure system and high pressure system. in low pressure system, sloped sumps are used to move the ash at low velocity and in high pressure system nozzle sprays used to ram up the speed of ash flow.
36.

## What would be the amount of distance that a low pressure system could carry the ash?

A. 25m
B. 500m
C. 150m
D. 800m
Explanation: low pressure system moves the ash mixed in water at a distance of 3 to 5 m/s in a sloped pump made of reinforced constituents and this movement is continuous. so, it has the ability to carry the ash for such long distance. there is no requirement any auxiliary source to move the ash mixed with water.
37.

## What is the capacity of low pressure hydraulic ash handling system?

A. 80 tonnes/hour
B. 22 tonnes/hour
C. 50 tonnes/hour
D. 10 tonnes/hour
Explanation: the capacity of low pressure hydraulic ash handling system is 50tonnes/hour at a speed of 3m/s. since the ash produced is mixed in water and dumped, the water has the ability to dissolve and intake more amount of ash. and this mixture is spread throughout the sump.
38.

## Which of these terms defines the pressure difference in the furnace?

A. draught
B. duct
C. stack
D. chimney
Explanation: the term ‘draught’ is used to define the static pressure in the furnace, in the various ducts and the stack.
39.

## 6 DRAUGHT SYSTEM

A. Δp = gh(ρa-ρg)
B. Δp = gh(ρg-ρa)
C. Δp = ghρg
D. Δp = gh(ρa+ρg)
Explanation: the draught produced is given by Δp = gh(ρa-ρg).
40.

## Which of these is not a type of mechanical draft system for a furnace?

A. balanced draft
B. induced draft
C. forced draft
D. actuated draft
Explanation: the three types of mechanical drafts are balanced, induced and forced drafts.
41.

## Stack heat losses can be minimised by

A. using low c.v. fuels
B. controlling the excess air
C. oxygen enrichment of combustion air
D. maintaining proper draft in the furnace
Answer» B. controlling the excess air
Explanation: excess amount of air leads to significant losses in energy due to heat loss through flue gases.
42.

## Which of these accentuates clinkering trouble on furnace grate burning coal?

A. low reactivity of carbonised residue containing high proportions of iron and sulphur
B. low forced draught and low fuel bed temperature
C. thick fire bed and preheated primary air
D. all of the mentioned
Answer» D. all of the mentioned
43.

## In a furnace employing forced draught compared to induced draught

A. the fan operates hot and hence blades are liable to corrosion and erosion
B. positive pressure exists in the furnace
C. air is sucked in, so air leaks are more and hence furnace efficiency is reduced
D. none of the mentioned
Answer» C. air is sucked in, so air leaks are more and hence furnace efficiency is reduced
Explanation: a positive pressure exists in the furnace employing forced draught.
44.

## Which of the following types of the fans has the highest cost?

A. centrifugal fans
B. axial fans
C. primary fans
D. gas recirculation fans
Explanation: axial fans have the highest cost.
45.

## Which of these is not a type of drive of variable speed control?

A. variable speed turbine
B. hydraulic coupling
C. multiple speed ac motor
Explanation: except ‘electronically adjustable turbine drive’, all other are a type of drive in variable speed control.
46.

## Feed water for boiler of thermal power plant is obtained from:

A. natural sources like river and lake
B. partly from condensed steam and natural sources
C. condensed steam and small percentage from natural resources
D. natural sources and small percentage from condensed steam
Answer» C. condensed steam and small percentage from natural resources
Explanation: the steam coming out of turbines is condensed and the condenset is fed back to the boiler. some of water losses due
47.

## Mechanical method of water treatment is done to

A. heat the feed water
B. to remove solid matter and impurities
C. to add some solid materials
D. to remove dissolved gases
Answer» B. to remove solid matter and impurities
Explanation: mechanical method of water
48.

## Which method is used in large modern thermal power plants to heat feed water?

A. open type heatre is used
B. close type heater is used
C. steam is directly taken from main turbine and used to heat it feed water
D. surface type heater is used
Answer» C. steam is directly taken from main turbine and used to heat it feed water
Explanation: open and contact type haters are in small power plants. such heaters recives steam from back pressure turbine. in large modern power plants heaters bleed steam from the main turbine and use it for heating of feed water.
49.

## Thermal treatment methods used to remove impurities like:

A. dissolved carbon dioxide and other gases
B. solid materials
C. carbonate
D. bacterial impurities
Answer» A. dissolved carbon dioxide and other gases
Explanation: thermal treatment method involves distillation and derative heating of feed water. during distillation water is evaporated then condensed and collected. during derating heating water is broken up into fine droplets and heated to produced vapour within the deaerator. during these process carbon dioxide and other days of devices separated from feet water.
50.

## Chemical method of treatment is used for treatment of:

A. diissolve gases
B. carbonate and carbon dioxide
C. bacterial impurities
D. send and suspended materials
Answer» B. carbonate and carbon dioxide
Explanation: chemical treatment involvs line treatment, soda treatment, lime and soda treatment. zeolite treatment and demineralisation. iime treatment is done for treatment of carbonate hardness, carbon dioxide in water. soda treatment is done for treatment of water containing non carbonate hardness and line soda treatment is used when both carbonate and none carbonate hardness for feed water.
51.

## A plant producing both, electrical power & process heat simultaneously is?

A. cogenital plant
B. cogenerial plant
C. cogeneration plant
D. conglomerate plant
Explanation: cogeneration plant is defined as a plant which produces electrical power and processes heat simultaneously.
52.

## In a back pressure turbine

A. pressure at the exhaust from the turbine is the saturation pressure corresponding to the temperature desired in the process
B. pressure at the entrance of the turbine is the saturation pressure corresponding to the temperature desired in the process
C. pressure at the exhaust from the turbine is the saturation pressure corresponding to the pressure desired in the process
D. none of the mentioned
Answer» A. pressure at the exhaust from the turbine is the saturation pressure corresponding to the temperature desired in the process
Explanation: the name back pressure turbine is given because pressure at the exhaust from the turbine is the saturation pressure corresponding to the temperature desired in the process.
53.

## In a by-product power cycle?

A. the power is produced initially
B. power production is in the middle stages of the cycle
C. power production is after the cycle has ended
D. none of the mentioned
Answer» C. power production is after the cycle has ended
Explanation: when the process steam is the basic need, and the power is produced
54.

## In terms of cost per MW compared to condensing sets of the same power, the back pressure turbines are?

A. more expensive
B. cheaper
C. costly
D. none of the mentioned
Explanation: back pressure turbines are usually small with respect to their power output because they have no great volume of exhaust to cope with, the density being high. they are usually single cylinder and hence, usually cheaper in terms of cost per mw.
55.

## Which of the following is a good medium for constant temperature heating?

A. water
B. steam
C. coolant
D. diesel
Explanation: for constant temperature heating (or drying), steam is a very good medium since isothermal condition can be maintained by allowing saturated steam to condense at that temperature and utilising the latent heat released for heating purposes.
56.

## If e is the electricity fraction of the total energy output, m is the electric plant efficiency and n is the steam generator efficiency; the heat added per unit total energy output is given by?

A. (1 / m) + ((1 – e) / n)
B. (1 / n) + ((1 – e) / m)
C. (1 / m) + ((1 + e) / n)
D. (1 / n) + ((1 – e) / m)
Answer» A. (1 / m) + ((1 – e) / n)
Explanation: if e is the electricity fraction of the total energy output, m is the electric plant efficiency and n is the steam generator efficiency; the heat added per unit total energy output is given by?
57.

## Which of these is not considered economical for cogeneration?

A. a high fraction of electric to total energy
B. a low fraction of electric to total energy
C. a low fraction of total energy to electric energy
D. none of the mentioned
Answer» B. a low fraction of electric to total energy
Explanation: a low fraction of electric to total energy is considered as an economical condition for cogeneration. cogeneration plant is defined as a plant which produces electrical power and processes heat simultaneously.
58.

## Which of these is a working fluid in the bottoming plant of a Brayton-Rankine combined plant?

A. mercury
B. steam
C. water
D. air
Explanation: water is the bottoming fluid due to its high specific heat capacity.
59.

## What would be the temperature of the gas in the combustion chamber?

A. 500 °c
B. 1600 °c
C. 1200 °c
D. 650 °c
Explanation: the gas in the combustion chamber is at a temperature of 1600 °c.
60.

## What is regeneration?

A. removal of heat from compressed air between stages of compression
B. transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber
C. to increase the temperature of partially expanded gases by burning more fuel
D. transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber and increases the temperature of partially expanded gases by burning more fuel
Answer» B. transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber
Explanation: transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber is called the process of regeneration.
61.

## What is meant by inter cooling?

A. removal of heat from compressed air between stages of compression
B. transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber
C. to increase the temperature of partially expanded gases by burning more fuel
D. none of the mentioned
Answer» A. removal of heat from compressed air between stages of compression
Explanation: removal of heat from compressed air between various stages of compression is called inter cooling.
62.

## What is the air standard cycle for a Gas- Turbine called?

A. reheat cycle
B. rankine cycle
C. brayton cycle
D. diesel cycle
Explanation: brayton cycle is an ideal air standard cycle for a gas turbine, which, like the rankine cycle, also comprises of two reversible adiabatic & two reversible isobars.
63.

## Power is produced when the working fluid does some work on the?

A. shaft
B. fins
D. none of the mentioned
Explanation: for the production of power, the working fluid does some work on the blades of the turbine, thereby producing power.
64.

## A Gas Turbine is which type of combustion plant?

A. external
B. open
C. internal
D. cannot say
Explanation: since for the production of
65.

## Which type of compressor is used in a gas turbine plant?

A. reciprocating compressor
B. screw compressor
C. multistage axial flow compressor
D. either reciprocating compressor & screw compressor
Answer» C. multistage axial flow compressor
Explanation: multistage axial flow compressor is the compressor in practical usage in a gas turbine plant.
66.

## What part or % of power developed is utilised for driving the compressor?

A. 65 %
B. 70 %
C. 55 %
D. 80 %
Explanation: a total of 65 % of power developed in the gas turbine is used for driving the compressor.
67.

## The gas turbine power plant mainly uses which among the following fuels?

A. coal and peat
B. kerosene oil and diesel oil and residual oil
C. gas oil
D. natural gas and liquid petroleum fuel
Answer» D. natural gas and liquid petroleum fuel
Explanation: natural gas and liquid petroleum fuel are among the two fuels used in a gas turbine.
68.

## The maximum steam temperature in a

A. 600
B. 500
C. 300
D. 100
Explanation: the maximum steam temperature in a power cycle is 600 degree centigrade.
69.

## The temperature in a dry bottom pulverised coal furnace, in degree Celsius is about?

A. 1200
B. 1300
C. 1400
D. 2000
Explanation: the temperature in a dry bottom pulverised coal furnace, in degree celsius is about 1300.
70.

## What happens to the availability in a combined cycle plant?

A. decreases
B. increases
C. remains same
D. cannot say
Explanation: there is a great thermal irreversibility & a decrease of availability because of heat transfer from combustion gases to steam through such a large temperature difference.
71.

## Which of the following is not a type of Combined Plant?

A. sodium- mercury-potassium plant
B. gas turbine-steam turbine plant
C. thermionic steam plant
D. thermoelectric steam plant
Explanation: sodium-mercury-potassium plants have two topping fluids which is impossible for a plant to possess.
72.

## Which of these is not a component of nuclear reactor?

A. reactor core
B. refractor
C. control rod
D. biological shield
Explanation: a reflector rather than a refractor is a component of nuclear reactor.
73.

## What efficiencies of thermionic power generator have been realised?

A. 50-60%
B. 40-50%
C. 10-20%
D. 30-40%
Explanation: efficiency of 30-40% has been realised in thermionic generators.
74.

## In economics of nuclear power plant taxes and insurance charges are taken as

A. operating cost
B. maintenance cost
C. capital cost
D. fixed cost
Explanation: the life of reactor plant may be taken as between 15 to 20 years. for the other parts of the plant equipment the life may be taken as 30 years. the fixed cost would be interest, depreciation, taxes and insurance charges.
75.

## PWR stands for

A. power
B. partially weathered rock
C. pressurized water reactor
D. packaging waste regulations
Explanation: pwr stands for pressurized water reactor. a pwr power plant consists of two loops in series. one is the coolant loop called primary loop and other is the water steam or working fluid loop. pressurized water reactor falls under the category of light water reactor.
76.

## What does the top of the pressurizer in pressurized water reactor consists of at primary system pressure?

A. steam
B. air
C. water
D. fluids
Explanation: the pressurizer is a pressure vessel with a heater at the bottom and water spray at the top. the top of the pressurizer is filled with steam at primary system pressure. if the primary loop pressure drops, the heater is energized to increase the steam content in the pressurizer and thus increases the pressure of primary cooling system.
77.

## Select the incorrect statement which supports PWR.

A. water is used as coolant
B. pwr is stable in operation
C. uses natural fuel
Explanation: pwr uses enriched fuel
78.

## Select the incorrect statement about PWR.

A. high primary circuit pressure requires a strong pressure vessel
B. corrosion is less in pwr
C. during fuel charging in pwr, the reactor has to be shut down at least for a month
D. pwr results in uneven heating
Answer» B. corrosion is less in pwr
Explanation: presence of high temperature and high pressure water, the corrosion is severe. this means use of stainless steel adds to further costing. when γ- radiations pass through the pressure vessel it results in uneven heating which induces thermal stresses on vessels.
79.

## LWR stands for

A. lower water reactor
B. line water reactor
C. liquefied water reactor
D. light water reactor
Explanation: the light water reactor is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator – furthermore a solid fissile element is used as fuel. these are most common type of thermal-neutron reactors.
80.

## In which reactor is the coolant in direct contact with the heat producing nuclear fuel?

A. fast breeder reactor
B. pressurized water reactor
C. boiling water reactor
D. heavy water reactor
Explanation: in boiling water reactor, the coolant is in direct contact with the heat producing nuclear fuel and boils in the same compartment in which the fuel is located. the reactor pressure is maintained at 70bar. the coolant thus serves the triple function of coolant, moderato and working fluid.
81.

## How many types of Boiling water reactor cycles are there?

A. 2
B. 3
C. 4
D. 5
Explanation: there are three different types of bwr cycles commonly used:
82.

## Which country invented CANDU heavy water reactor?

B. germany
C. russia
D. bolivia
Explanation: the candu is a canadian pressurized heavy water reactor design used to generate electric power. heavy water nuclear reactors and light water nuclear reactors differ in how they create and manage the complex physics of nuclear fission or
83.

## CANDU stands for

Explanation: the candu, for canada deuterium uranium, is a canadian pressurized heavy water reactor design used to generate electricity. the acronym refers to its deuterium oxide (heavy water) moderator and its use of (originally natural) uranium fuel.
84.

## Which reactor consists of both fertile and fissile material?

A. fast breeder reactor
B. pressurize water reactor
C. boiling water reactor
D. converter reactor
Explanation: if the reactor produces more fissionable material than it consumes, it is fast breeder reactor. the breeder fuel consists of both fertile and fissile material. the number
85.

## What is acronym of LMFBR?

A. liquid molecular fast boiling reactor
B. liquid metal fast breeder reactor
C. liquefied metal fast boiling reactor
D. liquid metal fast boiling reactor
Answer» B. liquid metal fast breeder reactor
Explanation: lmfbr stands for liquid
86.

## GCFBR stands for

A. gas conditioned fast breeder reactor
B. gas cooled fast breeder reactor
C. gas conditioned fast boiling reactor
D. gas cooled fast breeder reactor
Answer» B. gas cooled fast breeder reactor
Explanation: the gcfbr stands for gas cooled fast breeder reactor; it is cooled by helium gas at 85bar. also helium doesn’t become radioactive under neutron bombardment and hence secondary coolant is not needed.
87.

## Using Helium gas in GCFBR has many advantages.

A. true
B. false
Explanation: using helium as coolant posses less severe metallurgical and safety problems. heat transfer coefficient of helium is much superior than sodium with artificial roughening of fuel rod surfaces. low doubling time as compared to sodium cooled reactors.
88.

## Which reactor uses orthometaerhenyl and paratherphenyl as coolant and moderator?

A. liquid metal fast breeder reactor
B. gas cooled fast breeder reactor
C. organic substance cooled reactor
D. candu heavy water reactor
Answer» C. organic substance cooled reactor
Explanation: organic substance cooled reactor uses enriched uranium as fuel and a mixture of orthometaterhenyl and paratherphenyl as coolant and moderator, and boron control rods, generating 11.4 mw capacities with an overall efficiency of 25%.
89.

## Nuclear plant is located near the area where cooling water is available.

A. true
B. false
Explanation: some of the major factors to locate a nuclear station considered are, availability of cooling water, transportation facilities, distance from load centre, safety, radioactive waste, disposal facility and foundation requirement.
90.

## Which of the following may be used to measure the rate of nuclear disintegration?

A. geiger-muller counter
B. cold chamber
C. cyclotron
D. van de graph generator
Explanation: geiger-muller counter is used to measure the rate of nuclear disintegration.
91.

## Which of the following may not need a moderator?

A. candu reactor
B. fast breeder reactor
C. homogeneous reactor
D. none of the mentioned
Explanation: fast breeder reactor may not need a moderator.
92.

## Which of the following is not a naturally occurring nuclear fuel?

A. uranium-238
B. thorium-233
C. plutonium-239
D. none of the mentioned
Explanation: plutonium-239 is an artificial nuclear fuel.
93.

## One amu is equivalent to?

A. 931 mev
B. 93.1 ev
C. 9.31 ev
D. 931 j
Explanation: 91 mev constitutes one amu.
94.

## Fast breeder reactors do not

A. use molten sodium as coolant
B. use fast neutrons for fission
C. use th-232 as fissile fuel
D. convert fertile material to fissile material
Answer» C. use th-232 as fissile fuel
Explanation: fast breeder reactors do not use thorium-232 as fuel.
95.

## A boiling water reactor is the one, in which the

A. pressurised water is pumped into the core.
B. coolant water, after being heated in the reactor core, generates steam in a boiler
C. fuel and the coolant are thoroughly mixed to form a homogeneous solution
D. coolant water is allowed to boil in the core of the reactor
Answer» D. coolant water is allowed to boil in the core of the reactor
Explanation: a boiling water reactor is the one, in which the coolant water is allowed to boil in the core of the reactor.
96.

## Commercial power generation from fusion reactor is not yet possible, because

A. it is difficult to initiate fusion reaction
B. the fuel required (e.g. deuterium and tritium) is scarce
C. it is difficult to control fusion reaction
D. quantity of fuel required for initiating fusion reaction is prohibitively high
Answer» C. it is difficult to control fusion reaction
Explanation: as fission reactions are hard to be controlled, the commercial power generation is not yet possible.
97.

## Thermal shield is used in high powered nuclear reactors to

A. absorb the fast neutrons
B. protect the walls of the reactor from radiation damage
C. slow down the secondary neutrons
D. protect the fuel element from coming in contact with the coolant
Explanation: thermal shield is used in high powered nuclear reactors to protect the walls of the reactor from radiation damage.
98.

## Where was the first control fission of an atom carried out?

A. india
B. japan
C. russia
D. germany
Explanation: the first controlled fission of an atom was carried out in germany in 1938. nuclear fission is the splitting of the nucleus of the atom. this splitting of the nucleus results in energy that can be used for various purposes.
99.

## Which was the first country to develop an atomic bomb?

A. russia
B. united states
C. china
D. japan
Explanation: though germany is the first country where first controlled fission of an atom was carried, united state was the first country to develop an atomic bomb, which was subsequently dropped on the japanese cities hiroshima and nagasaki.
100.

A. 0.1%
B. 0.5%
C. 0.7%
D. 1.5%