Hydro-electric power plant (HEPP)
1.
Which of the following is the correct equation for
the electrical power generated by the hydroelectric power plant?
a) 75×0.736 wQHη Watt
b) (7.5/0.736) × wQHη Watt
c) 0.845 ×wQHη Watt
d) 9.81 ×wQHη
View Answer
Answer: c
Explanation: Rating of any power plant is expressed by its maximum output
power. These are large quantities so rating is given in mega watts.The
electrical power generated by this plant is proportional to specific weight of
water(w), water head(H), generation efficiency(η), flow rate of water(Q) and
acceleration due to gravity.
2.
Which of the following is not a requirement for
site selection of hydroelectric power plant?
a) Availability of water
b) Large catchment area
c) Rocky land
d) Sedimentation
View Answer
Answer: d
Explanation: Sedimentation may reduce the water storage capacity of reservoir
and may also cause damage to the turbine blades. Availability of water, large
catchment area and rocky land are primary requirements for site selection of
hydroelectric power plant.
3.
The amount of electrical energy that can be
generated by a hydroelectric power plant depends upon ___________
a) Head of water
b) Quantity of water
c) Specific weight of water
d) Efficiency of Alternator
View Answer
Answer: b
Explanation: Potential energy of large quantity of stored water is used by
hydroelectric power plant to generate electrical energy. Head of water is
important to get kinetic energy from that potential energy. Efficiency of
alternator represents that what percentage of input mechanical power it can
convert into electrical power.
4.
Potential energy of water is used to drive the
turbine.
a) True
b) False
View Answer
Answer: b
Explanation: When water falls, potential energy of water is converted into
kinetic energy. This kinetic energy is used to drive the turbine.
5.
Hydroelectric power plant is __________
a) Non-renewable source of energy
b) Conventional source of energy
c) Non-conventional source of energy
d) Continuous source of energy
View Answer
Answer: b
Explanation: Hydroelectric power plants are conventional source of energy.
About 16.6% of total electricity and about 70% of total renewable energy of
world is provided by hydroelectric power plants. They are not Non-renewable
because water is inexhaustible. It is not continuous source of energy because
its output fluctuates with change in flow rate of water with season.
6.
Hydroelectric power plant is generally located near
load centre.
a) True
b) False
View Answer
Answer: b
Explanation: Hydroelectric power plants are generally constructed in hilly
areas. These power plants are quite away from the load centre.
7.
Hydroelectric power plant is mainly located in
____________
a) Flat areas
b) Deserts
c) Hilly areas
d) Deltas
View Answer
Answer: c
Explanation: In order to get sufficient head, hydroelectric power plants are
constructed in hilly areas. In desert and flat areas sufficient water head
cannot be obtained. Deltas are not suitable for this because of high
sedimentation.
8.
Which statement about hydroelectric power plant is
wrong?
a) Efficiency of hydroelectric power plant does not reduce with age
b) Its construction coast is very high and takes a long time for erection.
c) It is very neat and clean plant because no smoke or ash is produced.
d) Meeting rapidly changing load demands is not possible in hydroelectric power
plant.
View Answer
Answer: d
Explanation: Fluctuating load demands can be met just by controlling the flow
of water using valves and gates. Due to its robust construction, its efficiency
does not fall with time. Statement ‘b’ is correct because construction of dam,
installation of alternator and turbines are very costly.
9.
Which of the following is not an advantage of
hydroelectric power plant?
a) no fuel requirement
b) low running cost
c) continuous power source
d) no standby losses
View Answer
Answer: c
Explanation: Output of such plants is never constant. This is because of their
dependency over flow rate of water in river which is seasonal. No fuel
requirement low running cost and no standby losses are advantages of
hydroelectric power plants.
10.
Which of the following statement is true about
hydroelectric power plant?
a) Hydroelectric power plants are multipurpose.
b) Due to non-uniform flow of water frequency control in such plants is very
difficult.
c) Hydroelectric power plant has high running cost
d) Water is used as fuel in hydroelectric power plant
View Answer
Answer: a
Explanation: It is because in addition to generation of electricity they are
also used for irrigation, flood control etc. Frequency control in such plants
is done easily just by controlling flow of water to the turbine through valves
and gates. Due to low maintenance cost and no fuel requirement running cost of
a plant is very low. Water is not fuel.
11. Which element of hydroelectric power plant prevents
the penstock from water hammer phenomenon?
a) Valves and Gates
b) Draft tubes
c) Spillway
d) Surge Tank
View Answer
Answer: d
Explanation: Sudden increase in water pressure in penstock due to closing of
gates is called water hammer. Surge tank is a tank at sufficient height ,
connected to penstock through riser pipe. It takes the rejected water and
relives the penstock from excessive water hammer pressure.
12. Dam having very wide base as compared to its height
is called _________
a) buttress dam
b) arch dam
c) earth dam
d) solid gravity dam
View Answer
Answer: c
Explanation: Buttress dams are the concrete dams supported on downstream side
by buttresses. Arc dams are concrete dams curved from upstream side. Earth dam
is a type of embankment dam and have rock filled inside the structure.
13. Spillway discharges the overflow water to the
downstream side when the reservoir is full.
a) True
b) False
View Answer
Answer: a
Explanation: A condition may arise during flood periods when water level
increases beyond the capacity of reservoir. In such conditions spillway acts as
safety valve.
14.Trash racks are built for ___________
a) discharging the water freely from the turbine exit to tailrace
b) preventing the turbine from ingress of floating and other materials
c) creating artificial head to store sufficient potential energy of water
d) controlling the opening of valves
View Answer
Answer: b
Explanation: Heavy solid materials flowing with water can damage the turbine
blades if not stopped. Trash racks are closely spaced flat bars which provides
narrow path from which such unwanted materials cannot pass.
15. Penstock in a hydroelectric power plant is
_____________
a) a pipe connected to runner outlet
b) nozzle that release high pressure water on turbine blades
c) a conduit connecting forebay to scroll case of turbine
d) a pipe connecting surge tank to dam
View Answer
Answer: c
Explanation: Penstocks are the conduit built of steel or reinforced concrete.
Penstock connects forebay or surge tank to scroll case of turbine. Their main
function is to carry water from dam to the turbine.
16. The pressure at the inlet or exit of the draft tube
should not be _________
a) less than one third of atmospheric pressure
b) greater than one third of atmospheric pressure
c) less than one atmospheric pressure
d) greater than one atmospheric pressure
View Answer
Answer: a
Explanation: Decrease in pressure in any portion of turbine below one third of
atmospheric pressure may cause vapour bubbles or cavities to form. This
phenomenon is called cavitation. Also to maintain continuity of flow without
vaporisation the pressure should not fall below vapour pressure of water.
17. Draft tube increases the operating head on the
turbine.
a) True
b) False
View Answer
Answer: a
Explanation: Draft tubes are the pipes of suitable diameter attached to the
runner outlet. Draft tube converts the pressure developed by water leaving from
turbine into kinetic energy. This in turn increases the operating head on
turbine.
18. Which statement about surge tank is wrong?
a) Ideal location of surge tank is at the turbine inlet
b) A decrease in load demands cause a rise in water level in surge tank
c) Surge tanks are totally closed to avoid entry of unwanted objects to
penstock
d) Surge tanks are installed to reduce harm effects of water hammer phenomenon
View Answer
Answer: c
Explanation: Function of surge tank is to relieve the penstock from excessive
water hammer pressure. It does so by receiving rejected flow of water into the
tank. A totally closed tank can not release pressure so usually surge tanks are
left open at the top.
19. Trash racks are located _____________
a) near tailrace
b) at the entrance of turbine
c) inside penstock
d) intake
View Answer
Answer: d
Explanation: Intake includes headworks at the entrance of conduit. Those
headworks include different structures, trash racks are one of them. Trash
racks are fitted directly at the intake to prevent the floating and other
materials from going into the conduit.
20. What is the function of booms?
a) It supports the dam
b) It supports the penstock
c) It divert the Icebergs from flowing into the penstock
d) To hold the turbine structure
View Answer
Answer: a
Explanation: Booms are the one of those structures made at the intake. They are
constructed to prevent unwanted solid materials from flowing into the penstock.
Solid materials like icebergs, wood logs or other heavy materials which may
cause damage to the turbine blades if reached there.
21. Kaplan turbine is _____________
a) axial flow turbine
b) inward flow turbine
c) tangential flow turbine
d) mixed flow turbine
View Answer
Answer: a
Explanation: In Kaplan turbine water strikes the turbine blades axially. That’s
why Kaplan turbine is an axial flow turbine. Kaplan turbines are special type
of turbines for low head applications.
22. Pelton turbines are used for __________________
a) medium head applications
b) low head applications
c) in steam power plants
d) for high head applications
View Answer
Answer: d
Explanation: Pelton turbines are impulse turbines and are suitable for high
head low flow plants. Pelton turbines consist of elliptical shaped buckets
along its Periphery. Water is released from nozzle to the buckets of turbine.
23. Francis turbines are the type of _____________
a) reaction turbines
b) radial flow turbine
c) impulse turbine
d) axial flow turbine
View Answer
Answer: a
Explanation: Francis turbines are inward mixed flow type reaction turbines.
Such turbines develop power partly due to velocity of water and partly due to
difference in pressure acting on the front and back of the runner blades.
24. Operating head of Francis turbine is __________
a) less than 30
b) less than 70 m
c) 30 to 200 m
d) more than 200 m
View Answer
Answer: c
Explanation: Francis turbines are medium head(30 to 200 m) and medium flow
turbines. Using it for low or high head will cause inefficient operation. Their
life is about decades so maintenance cost is low.
25. Which of the following is not a reaction turbine?
a) Francis turbine
b) Kaplan turbine
c) Pelton wheel turbine
d) Propeller turbine
View Answer
Answer: c
Explanation: When the entire pressure of water is converted into kinetic energy
in a nozzle and the jet thus formed drives the wheel then the turbine is called
impulse turbine. Pelton turbine works in similar way, so it is an impulse
turbine. Francis, Kaplan and propeller turbines are reaction turbines.
26.
Inside pressure of which of the following turbine
is equal to atmospheric pressure?
a) Fixed vane propeller turbine
b) Movable vane propeller turbine
c) Francis turbine
d) Pelton wheel turbine
View Answer
Answer: d
Explanation: Francis and propeller turbines are totally submerged in water, the
turbine casing is full of water. As the water flows through the turbine blades,
its pressure changes. Also the discharging water creates negative pressure
below the turbine blades. Pelton turbines are fitted in open air and water Jet
is forced into its blades by nozzel so it’s inside pressure is equal to atmospheric
pressure.
27. Francis turbine is suitable for medium head
hydroelectric power plant.
a) True
b) False
View Answer
Answer: a
Explanation: Francis turbines are medium head and medium flow turbines. Kaplan
turbines are low head high flow turbines. Pelton turbines are high head and low
flow turbines.
28.
Which turbine has highest speed?
a) Pelton wheel turbine
b) Francis turbine
c) Impulse turbine
d) Kaplan turbine
View Answer
Answer: d
Explanation: Francis turbine has a specific speed of 60 to 300 rpm. Specific
speed of Pelton turbine is lowest. Speed of Kaplan turbine is 2 to 3 times more
than that of Francis turbine.
29. Governing mechanism used in case of Pelton wheel
turbine is ________
a) guide vane
b) nozzle needle
c) control valve
d) dam gates
View Answer
Answer:b
Explanation: During load variation it is necessary to maintain the speed of the
alternator constant. This is achieved by controlling the flow of water entering
the turbine by the help of automatic adjustment of guide vanes for reaction
turbine and the nozzle needle is in case of impulse turbine. Such an operation
of speed regulation called governing and the system used to do this is called
governor.
30. Guide vanes are used as governor in Kaplan turbine.
a) True
b) False
View Answer
Answer: a
Explanation: Guide vanes are used as governor in Francis and Kaplan turbines.
These guide vanes controls the flow of water to the turbine and hence governs
the speed of rotation of turbine. Under different loading conditions the speed
of rotation of turbine is needed to be controlled for constant frequency
output.
Nuclear power plant
31. The efficiency of a nuclear power plant in comparison to a conventional thermal power plant is
(a) same
(b) more
(c) less
(d) may be less or mote depending on size
(e) unpredictable
(a)
same atomic number and different masses
(b) same chemical properties but different atomic numbers
(c) different masses and different atomic numbers
(d) different chemical properties and same atomic numbers
(e) same chemical properties and same atomic numbers
Ans: b
33. Atomic number of an element in the periodic table represents the numbers of
(a) protons in the nucleus
(b) electrons in me nucleus
(c) neutrons in the nucleus
(d) electrons in the atom
(e) neutrons in the atom
Ans: a
34. The mass number of a substance represents the sum of total number of
(a)
protons and neutrons in an atom
(b) protons and electrons in an atom
(c) neutrons and electrons in an atom
(d) protons and neutrons in a nucleus
(e) protons and electrons in a nucleus
Ans: d
35. Which is not identical for an atom and an isotope
(a)
mass number
(b) atomic number
(c) chemical properties
(d) position in periodic table
(e) all of the above
Ans: a
36. Amongst the following, the fissionable materials are
(a) U233andPu239
(b) U23iandPu233
(c) U235andPu235
(d) U238andPu239
(e) U243andPu235
Ans: a
37. A nuclear unit becoming critical means
(a) it is generating power to rated capacity
(b) it is capable of generating much more than rated capacity
(c) there is danger of nuclear spread
(d) chain reaction that causes automatic splitting of the fuel nuclei has been
established
(e) it generates no heat
Ans: d
38. Moderator in nuclear plants is used to
(a) reduce temperature
(b) extract heat from nuclear reaction
(c) control the reaction
(d) cause collision with the fast moving neutrons to reduce their speed
(e) moderate the radioactive pollution
Ans: d
39. The most commonly used moderator in nuclear plants is
(a) heavy water
(b) concrete and bricks
(c) graphite and concrete
(d) deuterium
(e) graphite
Ans: e
40. The nuclear energy is measured as
(a) MeV
(b) curie
(c) farads
(d) MW
(e) kWhr
Ans: a
41. The total energy released in fission of U is
(a)
5 MeV
(b) 10 MeV
(c) 199 MeV
(d) 168 MeV
(e) 11 MeV
Ans: c
42. Breeder reactor has a conversion ratio of
(a)
unity
(b) more than unity
(c) less than unity
(d) zero
(e) infinity
Ans: b
43. Boiling water reactor employs
(a) boiler
(b) direct cycle of coolant system
(c) double circuit system of coolant cycle
(d) multi pass system
(e) single circuit system
Ans: b
44. Fast breeder reactor uses
(a) boiler
(b) direct cycle of coolant system
(c) double circuit system of coolant cycle
(d) multi pass system
(e) single circuit system
45. One gram of uranium will produce energy equivalent to approximately
(a) 1 tonne of high grade coal
(b) 4.5 tonnes of high grade coal
(c) 10 tonnes of high grade coal
(d) 100 tonnes of high grade coal
(e) 1000 tonnes of high grade coal
46. Which of the following nuclear reactor does not need a heat exchanger for generation of steam
(a)
gas cooled
(b) liquid metal cooled
(c) pressurised water
(d) boiling water
(e) none of the above
Ans: d
47. The number of isotopes of hydrogen are
(a) 1
(b) 2
(c) U
(c) 3
(e) 0
Ans: c
48. The commonly used material for shielding is
(a) lead or concrete
(b) lead and tin
(c) graphite or cadmium
(d) thick galvanized sheets
(e) black carbon papers
Ans: a
49.The main interest of shielding in nuclear reactor is protection against
(a) X-rays
(b) infra-red rays
(c) a, P, and y rays
(d) neutrons and gamma rays
(e) electrons
Ans: d
50. Reflector in nuclear plants is used to
(a)
return the neutrons back into the core
(b) shield the radioactivity completely
(c) check polllution
(d) conserve energy
(e) is not used
Ans: a
Diesel Power Plant:
1. If the temperature of intake air in internal
combustion engine increases, then its efficiency will __________
a) remain same
b) increase
c) decrease
d) none of the mentioned
View Answer
Answer: c
Explanation: The efficiency of an IC Engine is inversely proportional to the
temperature of intake air.
2. The operation of forcing additional air under
pressure in the engine cylinder is known as __________
a) Supercharging
b) Scavenging
c) Turbulence
d) Pre-ignition
View Answer
Answer: a
Explanation: Supercharging is the operation of forcing additional air under
pressure in the engine cylinder.
3. The ignition quality of petrol is expressed by
__________
a) Cetane number
b) Octane number
c) Calorific Value
d) None of the mentioned
View Answer
Answer: b
Explanation: Octane number estimates the quality of petrol.
4. The mean effective pressure obtained from engine
indicator indicates the __________
a) maximum pressure developed
b) minimum pressure developed
c) instantaneous pressure at any point
d) average pressure
View Answer
Answer: d
Explanation: The mean effective pressure indicates the average pressure on the
engine.
5. The probability of knocking in diesel engines is
increased by __________
a) high self-ignition temperature
b) low volatility
c) high viscosity
d) all of the mentioned
View Answer
Answer: d
Explanation: The probability of knocking in diesel engines is increased by
keeping high self-ignition temperature, low volatility, high viscosity, etc.
6. Reactors for propulsion applications are designed
for__________
a) any form of uranium
b) natural uranium
c) enriched uranium
d) thorium
View Answer
Answer: c
Explanation: Enriched uranium is the material that is used for making reactors
for propulsion application.
7. What is the pour point of fuel oil?
a) Minimum temperature to which oil is heated in order to give off inflammable
vapours in sufficient quantity to ignite momentarily when brought in contact
with a flame
b) Temperature at which it solidifies or congeals
c) It catches fire without external aid
d) Indicated by 90% distillation temperature i.e., when 90% of sample oil has
distilled off
View Answer
Answer: b
Explanation: The temperature at which fuel oil solidifies or congeals is called
pour point of fuel oil.
8. What is the maximum temperature in the I.C. engine
cylinder is of the order of(in degree Celsius)?
a) 500-1000
b) 1000-1500
c) 1500-2000
d) 2000-2500
View Answer
Answer: d
Explanation: The maximum temperature in the I.C. engine cylinder is of the
order of(in degree Celsius) is 2000-25000 degree Celsius.
9. In compression ignition engines, swirl denotes a
__________
a) Haphazard motion of the gases in the chamber
b) Rotary motion of the gases in the chamber
c) Radial motion of the gases in the chamber
d) None of the mentioned
View Answer
Explanation: Swirl in a compression ignition engine denotes rotary motion of the gases in the chamber.
10.
Supercharging is
the process of __________
a) Supplying the intake of an engine with air at a density greater than the
density of the surrounding atmosphere
b) Supplying compressed air to remove combustion products fully
c) Providing excess temperature to the sucked in gases
d) None of the mentioned
View Answer
Answer: a
Explanation: Supercharging is the process of supplying the intake of an engine
with air at a density greater than the density of the surrounding atmosphere.
11.
The object of
supercharging the engine is __________
a) to increase the power output of an engine when greater power is required
b) to reduce mass of the engine per brake power
c) to reduce space occupied by the engine
d) all of the mentioned
View Answer
Answer: d
Explanation: Supercharging is done to increase the power output of an engine,
to reduce mass of the engine per brake power & to reduce space occupied by
the engine.
12.
The compensating
jet in a carburettor supplies almost constant amount of petrol at all speeds
because the __________
a) jet area is automatically varied depending on the suction
b) the flow from the main jet is diverted to the compensating jet with increase
in speed
c) flow is produced due to the static head in the float chamber
d) the diameter of the jet is constant and the discharge coefficient is
invariant
View Answer
Answer: c
Explanation: The compensating jet in a carburettor supplies almost constant
amount of petrol at all speeds because the flow is produced due to the static
head in the float chamber.
13.
The ratio of the
volume of charge admitted at N.T.P. to the swept volume of the piston is
called?
a) overall efficiency
b) mechanical efficiency
c) relative efficiency
d) volumetric efficiency
View Answer
Answer: d
Explanation: Volumetric Efficiency is the ratio of the volume of charge
admitted at N.T.P. to the swept volume of the piston.
14.
A moderator
generally used in nuclear power plants is?
a) heavy water
b) concrete
c) graphite & concrete
d) graphite
View Answer
Answer: c
Explanation: A moderator generally used in nuclear power plants is made up of
graphite & concrete.
15.
In a diesel
engine, the duration between the time of injection and ignition is known as?
a) delay period
b) period of ignition
c) burning period
d) pre-ignition period
View Answer
Answer: a
Explanation: In a diesel engine, the duration between the time of injection and
ignition, is known as the delay period.
16.
Nuclear Reactors
are used __________
a) to produce heat for thermoelectric power
b) to propel ships, submarines, aircrafts
c) to produce fissionable material
d) all of the mentioned
View Answer
Answer: d
Explanation: Nuclear reactors have wide range of usage which include producing
heat for thermoelectric power, ship propulsion, production of fissionable
materials, etc.
17.
Where reactor
operation is designed with fast neutrons such as in reactors using highly
enriched fuel, the moderator used is?
a) Carbon dioxide
b) Heavy Water
c) Graphite
d) No moderator is needed
View Answer
Answer: d
Explanation: Where reactor operation is designed with fast neutrons such as in
reactors using highly enriched fuel, no moderator is required.
18.
The expansion of
fuel in a four stroke cycle diesel engine __________
a) starts at 15° after top dead centre and ends at 30° before bottom dead
centre
b) starts at top dead centre and ends at 30° after top dead centre
c) may start and end anywhere
d) starts at 15° before top dead centre and ends at
30° after top dead centre
View Answer
Answer: a
Explanation: The expansion of fuel in a four stroke cycle diesel engine starts
at 15° after top dead centre and ends at 30° before bottom dead centre.
19.
A moderator, in nuclear power plants, is a medium
introduced into the fuel mass in order to __________
a) slow down the speed of fast moving neutrons
b) control the reaction
c) reduce the temperature
d) extract heat from nuclear reaction
View Answer
Answer: a
Explanation: A moderator, in nuclear power plants, is a medium introduced into
the fuel mass in order to slow down the speed of fast moving neutrons.
20.
The thermal efficiency of diesel engines is about
__________
a) 30%
b) 15%
c) 50%
d) 70%
View Answer
Answer: d
Explanation: The thermal efficiency of diesel engines is about 70%.
21.
In a four stroke cycle petrol engine, the charge is
ignited at __________
a) 30° after bottom dead centre
b) 30° before bottom dead centre
c) 30° after top dead centre
d) 30° before top dead centre
View Answer
Answer: d
Explanation: In a four stroke cycle petrol engine, the charge is ignited at 30°
before top dead centre.
22.
The exhaust valve in a four stroke cycle petrol
engine __________
a) opens at 50° after bottom dead centre and closes at 15° before top dead
centre
b) opens at 50° before bottom dead centre and closes at 15° after top dead
centre
c) opens at bottom dead centre and closes at top dead centre
d) may open and close anywhere
View Answer
Answer: b
Explanation: The exhaust valve in a four stroke cycle petrol engine opens at
50° before bottom dead centre and closes at 15° after top dead centre.
23.
The brake power of a diesel engine, keeping other
parameters constant, can be increased by __________
a) increasing the pressure of intake air
b) decreasing the density of intake air
c) decreasing the pressure of intake air
d) increasing the temperature of intake air
View Answer
Answer: a
Explanation: The brake power of a diesel engine, keeping other parameters
constant, can be increased by increasing the pressure of intake air.
24.
In a four stroke cycle, the minimum temperature
inside the engine cylinder occurs at the __________
a) end of suction stroke
b) beginning of exhaust stroke
c) beginning of suction stroke
d) end of exhaust stroke
View Answer
Answer: c
Explanation: In a four stroke cycle, the minimum temperature inside the engine
cylinder occurs at the beginning of exhaust stroke.
25.
The effective inhibitor of pre-ignition is
__________
a) alcohol
b) lead
c) water
d) none of the mentioned
View Answer
Explanation: Water is the most effective inhibitor of pre-ignition.
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