Question Bank for Railways NTPC (Technical Ability) Power Plant Engineering Power Plant Engineering

List-I		List-II
A.	Coolant	1.	Low neutron absorption
B.	Moderator	2.	Low radiation damage
C.	Fuel	3.	High heal transfer coefficient
D.	Shield	4.	High absorption of radiation.

Codes:

A)

A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]2

B)

A\[\to \]3, B\[\to \]1, C\[\to \]2, D\[\to \]4

C)

A\[\to \]1, B\[\to \]4, C\[\to \]4, D\[\to \]2

D)

A\[\to \]1, B\[\to \]3, C\[\to \]2, D\[\to \]4

View Solution

18)

Consider the following statements:

1. Pulverised fuel gives high and controlled burning rate.

2. Insufficient air causes excessive smoking of exhaust.

3. Excess air is provided to control the flue gas temperature

4. Effect of sulphur in fuel is to give high heat transfer rate.

Witch of these statements are correct?

A)

3 and 4

B)

2 and 3

C)

1 and 2

D)

1 and 4

View Solution

19)

Consider the following:

The essential boiler mountings would include.

A)

1, 3 and 4

B)

3 and 4

C)

1, 2 and 3

D)

1, 2 and 4

View Solution

20)

Which one of the following gaseous fuels does not have different higher and lower calorific values?

A)

Methane

B)

Ethane

C)

Carbon monoxide

D)

Hydrogen

View Solution

21)

Consider the following statements regarding an impulse turbine:

1. Relative velocity at the inlet and exit of the rotor blades are the same.

2. Absolute velocity at the inlet and exit of the rotor blades are the same. .

3. Static pressure within the rotor blade channel is constant.

4. Total pressure within the blade channel is constant.

Of these statements

A)

1 and 4 are correct

B)

2 and 3 are correct

C)

1 and 3 are correct

D)

2 and 4 are correct

View Solution

22)

The circulation ratio for once through steam generators is:

A)

1

B)

2

C)

2.5

D)

5

View Solution

23)

Consider the following accessories:

1. Superheater

2. Air pre-heater

3. Economizer

The correct sequence of the position of these accessories along the flow of flue gas in a steam power plant is:

A)

3, 1, 2

B)

1, 2, 3

C)

1, 3, 2

D)

2, 1, 3

View Solution

24)

Inside a large power boiler, the flue gas pressure will be above the atmospheric pressure:

A)

At the furnace

B)

nearsuperheater region

C)

At the base of the chimney

D)

After the forced draught fan

View Solution

25)

Steam enters a diffuser at Mach number 2.5 and exits at Mach number 1.8. The shape of the diffuser is:

A)

Divergent

B)

Convergent

C)

Convergent - divergent

D)

Divergent - convergent

View Solution

26)

Shock waves in nozzles would occur while turbines arc operating:

A)

At overload conditions

B)

At part load conditions

C)

Above critical pressure ratio

D)

At all off-design conditions

View Solution

27)

Steam enters the rotor of a reaction turbine with an absolute velocity of 236 m/s and relative velocity of 132 m/s. It leaves the rotor with a relative velocity of 232 m/s and absolute velocity of 126 m/s. The specific work output is:

A)

36.3 kW

B)

40.1 kW

C)

43.8 kW

D)

47.4 kW

View Solution

28)

The work output from a reaction turbine stage is 280 kW per kg/s of steam. If the nozzle efficiency is 0.92 and rotor efficiency is 0.90, the isentropic static enthalpy drop will be:

A)

352 kW

B)

347 kW

C)

338 kW

D)

332 kW

View Solution

29)

In a steam turbine, the enthalpy drops in the fixed blade and moving blade are 48 kJ and 32 kJ respectively. The degree of reaction is:

A)

40%

B)

55%

C)

60%

D)

66.6%

View Solution

30)

When the water level in the boiler falls to an unsafe limit, safety is ensured by the:

A)

Stop valve

B)

Safety valve

C)

Fusible valve

D)

blow-off cock

View Solution

31)

Large temperature rise of boiler feed water in the economiser should be avoided because:

A)

The economiser efficiency will reduce

B)

The overall steam generator efficiency will reduce

C)

Effectiveness of regenerator will he lower

D)

Flue gas will cool to dew point

View Solution

32)

Consider the following statements:

The erosion of steam turbine blades increases with the increase of

1. Moisture in the steam

2. Blade speed

Which of these statement (s) is/are correct?

A)

1 alone

B)

2 alone

C)

1 and 2

D)

Neither 1 nor 2

View Solution

33)

Consider the following statements:

Steam turbines are suitable for use as prime movers for large steam power plants because

1. A single steam turbine can be designed for a capacity of 1000 MW or more

2. Much higher speed may he possible as compared to a reciprocating engine

3. They are more compact when compared to a gas turbine power plant

4. The maintenance cost and running cost may not increase with years of service.

Which of these statements are correct?

A)

1, 2 and 3

B)

2, 3 and 4

C)

1, 2 and 4

D)

1, 3 and 4

View Solution

34)

Which one of the following types of nuclear reactor does not require a heat exchanger?

A)

Boiling water

B)

Pressurized water

C)

Sodium-cooled

D)

Gas-cooled

View Solution

35)

Consider the following statements regarding nuclear reactors:

1. A mixture of radioactive materials is used as fuel

2. Spent fuel is reprocessed to recover thorium/ plutonium

3. Control rods are made of zirconium

4. Spent fuel is fully disposed of safely, as waste.

Which of these statements are correct?

A)

1 and 2

B)

3 and 4

C)

1 and 3

D)

1, 3 and 4

View Solution

36)

Match List-I witn List-II regarding nuclear reactor and select the correct answer using the codes given below the lists:

List-I		List-II
A.	Moderator	1.	U-233
B.	Biological shield	2.	Hafnium
C.	Poison	3.	Beryllium
D.	Nuclear fuel	4.	Sodium
		5.	Lead

Codes:

A)

A\[\to \]3, B\[\to \]2, C\[\to \]5, D\[\to \]1

B)

A\[\to \]4, B\[\to \]5, C\[\to \]2, D\[\to \]3

C)

A\[\to \]3, B\[\to \]5, C\[\to \]2, D\[\to \]1

D)

A\[\to \]4, B\[\to \]2, C\[\to \]1, D\[\to \]3

View Solution

37)

Dryness fraction of steam means the mass ratio of:

A)

Wet steam to dry steam

B)

Dry steam to water particles in steam

C)

Water particles to total steam

D)

Dry steam to total steam.

View Solution

38)

A nucleus \[_{92}{{A}^{235}}\] emits alpha and beta particle and is converted to the nucleus \[_{82}Bu.\] the total number of alpha and beta particles emitted in the reaction is 11. Their respective numbers are:

A)

5 and 6

B)

7 and 4

C)

4 and 7

D)

6 and 5

View Solution

39)

Amount of oxygen needed to completely bum 1 kg of methane \[(C{{H}_{4}})\] is:

A)

2 kg

B)

4 kg

C)

16 kg

D)

22 kg

View Solution

40)

There is no steam drum in:

A)

La Mont boiler

B)

Loeffler boiler

C)

Benson boiler

D)

Velox boiler

View Solution

41)

Match List-I (Equipments) with List-II (Types) and select the correct answer using the codes given below the lists:

List-I		List-II
A.	Steam trap	1.	Fire tube type
B.	Water-level indicator	2.	Boiler mounting
C.	Cornish boiler	3.	Drumless type
D.	Benson boiler	4.	Boiler accessory
		5.	Indirectly heated

Codes:

A)

A\[\to \]2, B\[\to \]4, C\[\to \]3, D\[\to \]5

B)

A\[\to \]2, B\[\to \]4, C\[\to \]5, D\[\to \]3

C)

A\[\to \]4, B\[\to \]2, C\[\to \]1, D\[\to \]5

D)

A\[\to \]4, B\[\to \]2, C\[\to \]1, D\[\to \]3

View Solution

42)

The function of an economizer in a steam power plant is to:

A)

Increase the temperature of air supplied to a boiler

B)

Increase the enthalpy of feed water

C)

Condense the exhaust steam from the turbine

D)

Heat the fuel before combustion.

View Solution

43)

Consider the following statements:

A tube, with the section diverging in the direction of flow, can be used as

1. Supersonic nozzle

2. Subsonic nozzle

3. Supersonic diffuser

4. Subsonic diffuser

Select the correct answer using the codes given below:

A)

1 alone

B)

3 alone

C)

1 and 4

D)

2 and 3

View Solution

44)

A nozzle is discharging steam through critical pressure ratio. When the back pressure is further decreased, the nozzle flow rate will:

A)

Decrease

B)

Increase

C)

Remain unaltered

D)

First increase to maximum and then will decrease

View Solution

45)

The half-life of radioactive radon is 3.8 days. The time at the end of which l/20th of the Radon sample will remain undecayed will be:

A)

3.8 days

B)

16.5 days

C)

33 days

D)

76 days

View Solution

46)

Ratio of enthalpy drop in moving blades to the total enthalpy drop in the fixed and moving blades is called:

A)

Reheat factor

B)

Blade efficiency

C)

Degree of reaction

D)

internal efficiency

View Solution

47)

Maximum blade efficiency of a Parson's turbine is given by: (\[\alpha \] is nozzle angle)

A)

\[\frac{{{\cos }^{2}}\alpha }{1+2{{\cos }^{2}}\alpha }\]

B)

\[\frac{\cos \alpha }{1+2{{\cos }^{2}}\alpha }\]

C)

\[\frac{2{{\sin }^{2}}\alpha }{1+2{{\sin }^{2}}\alpha }\]

D)

\[\frac{2{{\cos }^{2}}\alpha }{1+2{{\cos }^{2}}\alpha }\]

View Solution

48)

The most efficient ideal regenerative steam power cycle is:

A)

Rankine cycle

B)

Carnot cycle

C)

Brayton cycle

D)

Joule cycle

View Solution

49)

In modem steam plants using pulverized fuel firing, the flue gases:

A)

First pass through air preheaters and then through economizer

B)

First pass through economizer and then through air preheaters

C)

Pass simultaneously through air preheaters and economizer which are connected in parallel

D)

Pass through economizer only.

View Solution

50)

Consider the following statements:

The purpose of reheating the steam in a steam turbine power plant is to

1. Increase specific output

2. Increase turbine efficiency

3. Reduce the turbine speed

4. Reduce specific steam consumption.

Which of the statements are correct?

A)

2 and 4

B)

1 and 3

C)

1, 2 and 4

D)

1, 3 and 4

View Solution

51)

A sodium graphite reactor uses sodium:

A)

As coolant and graphite as moderator

B)

As moderator and graphite as coolant

C)

With graphite as moderator and water as coolant

D)

As moderator and sodium, graphite and water together as coolant.

View Solution

52)

Purpose of moderator in nuclear reactor is to:

A)

Slow down the neutrons produced in fission

B)

Reduce nuclear pollution

C)

Control the reactor temperature so that protons produced are less

D)

Moderate the steam pressure to slow down the chain reaction.

View Solution

53)

In Fast Breeder Reactor:

A)

The moderator used is water

B)

The moderator used is graphite

C)

The moderator used is carbon dioxide

D)

No moderator is used.

View Solution

54)

If the enthalpies at the entry and exit of a nozzle are 3450 kJ/kg and 2800 kJ/kg and the initial velocity is negligible, then the velocity at the exit is:

A)

806.2 m/s

B)

25.5 m/s

C)

36 m/s

D)

1140.2 m/s

View Solution

55)

A nozzle is said to have choked flow when

1. Discharge is maximum.

2. Throat velocity is sonic.

3. Nozzle exit pressure is more than the critical pressure.

4. Discharge is zero

Select the correct answer using the codes given below:

A)

1 only

B)

1 and 2

C)

4 only

D)

1, 2 and 3

View Solution

56)

Consider the following characteristics:

1. High steam and blade velocities

2. Low steam and blade velocities

3. Low speeds of rotation

4. High carry-over loss

Which of these characteristics are possessed by a simple impulse turbine?

A)

1 and 2

B)

2 and 3

C)

1 and 4

D)

3 and 4

View Solution

57)

In a simple impulse turbine, the nozzle angle at the entrance is \[30{}^\circ .\] what will be the blade-speed ratio for maximum diagram efficiency?

A)

0.433

B)

0.25

C)

0.5

D)

0.75

View Solution

58)

In a two-row Curtis stage with symmetrical blading:

A)

Work done by both rows of moving blades are equal

B)

Work done by the first row of moving blades is double of the work done by second row of moving blades

C)

Work done by the first row of moving blades is three times the work done by second row of moving blades

View Solution

59)

In reaction turbines, with reduction of inlet pressure:

A)

The blade heights increase as the specific volume of steam decrease.

B)

The blade heights increase as the specific volume of steam increases

C)

The blade heights decrease as the specific volume of steam increases

D)

The blade heights decrease as the specific volume of the steam decreases.

View Solution

60)

If the enthalpy drops of moving blade and fixed blade of a stage in a reaction turbine are 9 and 11 kJ/kg respectively, then degree of reaction of stage is:

A)

0.1

B)

0.45

C)

0.55

D)

1.0

View Solution

61)

Which of the following combustion systems requires maximum excess air?

A)

Pulverized coal combustion

B)

Oil burners

C)

Gas burners

D)

Chain grate stoker

View Solution

62)

Match List-I with List-II and select the correct answer using the codes given below the lists:

List-I		List-II
A.	Fuel	1.	Graphite
B.	Cladding	2.	Natural Uranium
C.	Coolant	3.	Magnox
D.	Moderator	4.	\[C{{O}_{2}}\]

Codes:

A)

A\[\to \]1, B\[\to \]4, C\[\to \]3, D\[\to \]2

B)

A\[\to \]2, B\[\to \]4, C\[\to \]4, D\[\to \]1

C)

A\[\to \]1, B\[\to \]3, C\[\to \]4, D\[\to \]2

D)

A\[\to \]2, B\[\to \]4, C\[\to \]3, D\[\to \]1

View Solution

63)

If k is the ratio of the rate of production of neutrons to the rate of loss of neutrons, the reactor is called a critical reactor, when:

A)

k = 0

B)

0 < k < 1

C)

k = 1

D)

k >1

View Solution

64)

The most commonly used moderator in nuclear power plants is:

A)

Heavy water

B)

concrete and bricks

C)

Steel

D)

graphite

View Solution

65)

Consider an actual regenerative Rankine cycle with one open feed water heater. For each kg steam entering the turbine, m kg steam with a specific enthalpy of \[{{h}_{1}}\] is bled from the turbine. Specific enthalpy of water entering the heater is \[{{h}_{2}}.\] The specific enthalpy saturated liquid leaving the heater is equal to:

A)

\[m{{h}_{1}}-({{h}_{2}}-{{h}_{1}})\]

B)

\[{{h}_{1}}-m\,({{h}_{2}}-{{h}_{2}})\]

C)

\[{{h}_{2}}-m\,({{h}_{2}}-{{h}_{1}})\]

D)

\[m{{h}_{2}}-({{h}_{2}}-{{h}_{1}})\]

View Solution

66)

In the case of supersaturated steam flow through a nozzle, which of the following statements are correct?

1. Availability increases

2. Mass flow coefficient is greater than unity.

3. Nozzle velocity coefficient is less than unity.

Select the correct answer using the codes given below:

Codes:

A)

1, 2 and 3

B)

1 and 2

C)

2 and 3

D)

1 and 3

View Solution

67)

Which of the following thermal power plants will have the highest overall thermal efficiency?

A)

Steam power plant

B)

Gas turbine power plant

C)

Combined gas and steam power plant

D)

Diesel power plant

View Solution

68)

The function of the moderator in nuclear reactor is to:

A)

Stop chain reaction

B)

Reduce the speed of the neutrons

C)

Absorb neutrons

D)

Reduce temperature

View Solution

69)

Match List-I (Feature) with List-II (Turbine/ Staging and select the correct answer using the codes given below the lists:

List-I (Feature)		List-II (Turbine/Staging)
A.	Single stage impulse turbine	1.	Person's turbine
B.	Pressure compounding	2.	de Laval turbine
C.	Velocity compounding	3.	Rateau staging
D.	Reaction turbine	4.	Curtis staging

Codes:

A)

A\[\to \]4, B\[\to \]1, C\[\to \]2, D\[\to \]3

B)

A\[\to \]2, B\[\to \]3, C\[\to \]4, D\[\to \]1

C)

A\[\to \]4, B\[\to \]3, C\[\to \]2, D\[\to \]1

D)

A\[\to \]2, B\[\to \]1, C\[\to \]4, D\[\to \]3

View Solution

70)

In steam and other vapour cycles, the process of removing non-condensable is called:

A)

Scavenging process

B)

Depuration process

C)

Exhaust process

D)

Condensation process

View Solution

71)

Which of the following are fertile materials?

A)

\[{{U}^{33}}\] and \[P{{u}^{239}}\]

B)

\[{{U}^{238}}\] and \[T{{h}^{239}}\]

C)

\[{{U}^{238}}\] and \[T{{h}^{232}}\]

D)

\[{{U}^{235}}\] and \[P{{u}^{236}}72\]

View Solution

72)

S.I unit for radioactivity is:

A)

Joule

B)

amu

C)

Curie

D)

Becquerel

View Solution

73)

Which one of the following is the purpose of the purpose of blow down in a boiler?

A)

To control drum level

B)

To control solid concentration in the boiler water

C)

To increase the steam temperature

D)

To lower the steam temperature

View Solution

74)

Steam flows at the rate of 10 kg/s through a supersonic nozzle. Throat diameter is 50 mm. Density ratio and velocity ratio with reference to throat and exit are respectively 2.45 and 0.8. What is the diameter at the exit'?

A)

122.5 mm

B)

58 mm

C)

70 mm

D)

62.5 mm

View Solution

75)

An attemparator is used in some utility boilers:

A)

Ahead of super heater for initial superheating.

B)

For optimizing steam output from the generator

C)

To regulate steam pressure

D)

To control degree of superheat.

View Solution

76)

What is the purpose of moderator in a nuclear reactor?

A)

Moderate the fission temperature

B)

Reduce the speed of fast moving neutrons

C)

Reduce \[\beta \] and \[\gamma \] rays

D)

Absorb excess neutrons in the reactor

View Solution

77)

What is the efficiency of an ideal regenerative Rankine cycle power plant using saturated steam at \[327{}^\circ C\] and pressure 135 bar at the inlet to the turbine, and condensing temperature of \[27{}^\circ C\] (corresponding saturation pressure of 3.6 kPa)?

A)

92%

B)

33%

C)

50%

D)

42%

View Solution

78)

In a coupled separating and throttling calorimeter, 0.9 is the dryness fraction of steam in the separating unit and 0.95 is the dryness fraction in the throttling unit. What is the approximate value of the dryness fraction of the steam sample?

A)

0.855

B)

0.925

C)

0.947

D)

0.950

View Solution

79)

Consider the following statements:

1. Fusible plug is a device used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit.

2. Superheater is a device used to increase the temperature of saturated steam without raising its pressure.

3. An economizer decreases the steam raising capacity of boiler

Which of the above statements is/are correct?

A)

1 and 2

B)

2 and 3

C)

1 only

D)

1, 2 and 3

View Solution

80)

What is the cause of reheat factor in a steam turbine?

A)

Reheating

B)

Superheating

C)

Super saturation

D)

Blade friction

View Solution

81)

In a simple turbine, the nozzle angle at the entrance \[30{}^\circ .\] what is the blade speed ratio for maximum diagram efficiency?

A)

0.25

B)

0.5

C)

0.433

D)

0.125

View Solution

82)

Match List-I (Reactor) with List-II (Characteristic) and select the correct answer using the code given below the lists:

List-I (Rector)		List-II (Characteristic)
A.	Heterogeneous reactor	1.	May not need moderator
B.	Candu reactor	2.	Natural uranium fuelled and heavy water cooled
C.	Boiling water reactor	3.	Fuel and moderator are at different phases
D.	Fast breeder reactor	4.	Coolant water boils in the case of the reactor

Codes:

A)

A\[\to \]3, B\[\to \]4, C\[\to \]2, D\[\to \]1

B)

A\[\to \]1, B\[\to \]2, C\[\to \]4, D\[\to \]3

C)

A\[\to \]3, B\[\to \]2, C\[\to \]2, D\[\to \]1

D)

A\[\to \]1, B\[\to \]4, C\[\to \]4, D\[\to \]3

View Solution

83)

Match List-I (Name of Boiler) with List-II (Type) and select the correct answer using the rode given below the lists:

List-I (Name of Boiler)		List-II (Type)
A.	Stirling	1.	Bent water tube
B.	Cochran	2.	Once through flow
C.	Lancashire	3.	Vertical fire tube
D.	Benson	4.	Incline water tube
		5.	Horizontal fire tube

Codes:

A)

A\[\to \]2, B\[\to \]5, C\[\to \]4, D\[\to \]1

B)

A\[\to \]1, B\[\to \]3, C\[\to \]5, D\[\to \]2

C)

A\[\to \]2, B\[\to \]3, C\[\to \]5, D\[\to \]1

D)

A\[\to \]1, B\[\to \]5, C\[\to \]4, D\[\to \]2

View Solution

84)

In a steam power plant what is the outcome of regenerative feed heating?

1. Increase in specific output

2. Increase in cycle efficiency

3. Improved quality of exhaust steam

4. Reduced condenser load

Select the correct answer using the code given below:

A)

1 and 3 only

B)

2 only

C)

2 and 4

D)

1, 2 and 3

View Solution

85)

Consider the following statements in the context of high pressure boilers:

1. The tendency of scale formation is eliminated due to high velocity of water through tubes.

2. The heat transfer coefficient is increased by increasing the velocity of water through tubes.

3. The steam can he raised quickly to meet the variable load.

Which of the statements given above are correct?

A)

1 and 2 only

B)

2 and 3 only

C)

1 and 3 only

D)

1, 2 and 3

View Solution

86)

Why is enriched Uranium required as fuel when ordinary water is used as a moderator?

A)

Ordinary water has low moderating efficiency

B)

Ordinary water has high moderating absorption

C)

Ordinary water has high moderating efficiency

D)

Ordinary water has low neutron absorption.

View Solution

87)

Which one of the following gases is normally not used as a coolant in nuclear reactor?

A)

Hydrogen

B)

Helium

C)

Carbon dioxide

D)

Nitrogen

View Solution

88)

Which one of the following is correct? De Laval turbine is a

A)

Simple reaction turbine

B)

Simple impulse turbine

C)

Velocity compounded impulse turbine

D)

Pressure compounded impulse turbine

View Solution

89)

Which one of the following is the correct statement? Reheating of steam under ideal conditions takes place at constant

A)

Entropy

B)

enthalpy

C)

Pressure

D)

temperature

View Solution

90)

Consider the following statements about reactors:

1. Candu reactor is a natural uranium fuelled, heavy water cooled and moderated reactor.

2. In a pressurized water reactor the coolant water boils in the core of the reactor

3. Liquid metal is preferred as a coolant in case of a homogeneous reactor.

Which of the statements given above is/are correct?

A)

1 only

B)

2 only

C)

1 and 3 only

D)

1, 2 and 3

View Solution

91)

What is the material of thick walled canisters in which nuclear waste is buried deep?

A)

Zirconium

B)

Lead

C)

Stainless steel

D)

Tin

View Solution

92)

An isentropic nozzle is discharging steam at the critical pressure ratio. When the back pressure is further decreased, which one of the following will take place?

A)

Nozzle flow decreases

B)

Nozzle flow increases

C)

Nozzle flow will first increase, reach a maximum and then decrease

D)

Nozzle flow will remain unaltered.

View Solution

93)

How does entropy change when the super saturation occurs in a steam nozzle?

A)

The entropy decreases

B)

The entropy increases

C)

The entropy decreases and then increases

D)

The entropy increases and then decreases.

View Solution

94)

Consider the following statements in respect of nozzles:

1. The nozzle efficiency is defined as the ratio of the actual enthalpy drop to the isentropic enthalpy drop between the same pressures.

2. Velocity coefficient is defined as the ratio of exit velocity when the flow is isentropic, to the actual velocity.

3. The included angle of divergence is usually kept more than \[20{}^\circ .\]

Which of the statements given above is/are correct?

A)

1 only

B)

1 and 2 only

C)

3 only

D)

1, 2 and 3

View Solution

95)

In a convergent-divergent steam nozzle, the flow is supersonic at which location?

A)

Entrance of the nozzle

B)

Throat

C)

Converging portion of the nozzle

D)

Diverging portion of the nozzle

View Solution

96)

A fast breeder reactor uses which one of the following as fuel?

A)

Thorium

B)

\[{{U}^{235}}\]

C)

Plutonium

D)

Enriched uranium

View Solution

97)

Consider the following statements:

1. Heat is generated in a nuclear reactor by fission of U-235 by neutron.

2. Percentage of U-238 in natural Uranium is around 0.71.

3. Plutonium is not a naturally occurring nuclear fuel.

Which of the statements given above is/are correct?

A)

1 only

B)

2 and 3 only

C)

1 and 3 only

D)

1, 2 and 3

View Solution

98)

Match List-I with List-II and select the correct answer using the code given below the lists:

List-I (Turbine Performance Factor)		List-II (Definition)
A.	Reheat factor	1.	\[\frac{Adiabatic\,\,heat\,\,drop}{heat\,\,\text{supplied}}\]
B.	Internal efficiency	2.	\[\frac{Total\,\,work\,\,done\,\,on\,\,the\,\,motor}{Total\,\,adiabatic\,\,heat}\]
C.	Degree or reaction	3.	\[\frac{Cumulative\,\,heat\,\,drop\,\,of\,\,all\,\,stages}{Total\,\,adiabatic\,\,heatdrop}\]
D.	Rankine efficiency	4.	\[\frac{Enthalpy\,\,drop\,\,in\,\,moving\,\,blades}{Enthalpy\,\,drop\,\,in\,\,the\,\,stage}\]

Codes:

A)

A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1

B)

A\[\to \]4, B\[\to \]1, C\[\to \]3, D\[\to \]2

C)

A\[\to \]4, B\[\to \]2, C\[\to \]3, D\[\to \]1

D)

A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]2

View Solution

99)

The enthalpy of steam entering a, turbine in a Rankine cycle is 3200 kJ/kg. The enthalpy after isentropic expansion is 2400 kJ/kg and the enthalpy at the end of actual expansion is 2560 kJ/kg. What is the turbine efficiency?

A)

75%

B)

80%

C)

85%

D)

90%

View Solution

100)

For a steam jet angle of \[30{}^\circ \] (from the tangential direction) at the entrance, what is the maximum blade efficiency (approximate) of a Parson's turbine?

A)

0.85

B)

0.49

C)

0.4

D)

0.3

View Solution

101)

In a reaction turbine enthalpy drop per stage is 60 unit while the enthalpy drop in the moving blade is 32 unit. What is the degree of reaction?

A)

0.28

B)

0.46

C)

0.53

D)

1.87

View Solution

102)

Where is shock effect felt in a nozzle?

A)

Divergent portion

B)

Entrance

C)

Convergent portion

D)

Throat

View Solution

103)

What is the value of the Mach number in the convergent portion of a steam nozzle?

A)

One

B)

zero

C)

> 1

D)

\[>1(\ne 0)\]

View Solution

104)

Consider the following statements:

1. In a nozzle, if the fluid velocity is greater than the local sound velocity, the duct must converge.

2. In a diffuser, if the fluid velocity is greater than the local sound velocity, then the duct must converge.

Which of the statements given above is/are correct?

A)

1 only

B)

2 only

C)

Both 1 and 2

D)

neither 1 nor 2

View Solution

105)

For a convergent nozzle, what is the correct expression for the critical pressure, if the inlet pressure is \[{{P}_{1}}?\]

A)

\[{{p}_{1}}{{\left( \frac{2}{\gamma +1} \right)}^{\gamma /\gamma -1}}\]

B)

\[{{p}_{1}}{{\left( \frac{\gamma +1}{2} \right)}^{\gamma /\gamma -1}}\]

C)

\[{{p}_{1}}{{\left( \frac{2}{\gamma +1} \right)}^{\gamma -1/\gamma }}\]

D)

\[{{p}_{1}}{{\left( \frac{\gamma +1}{2} \right)}^{2\gamma /\gamma -1}}\]

View Solution

106)

Witch of the following we the advantages of surface condenser?

1. Less quantity of makeup water is required.

2. It is suitable for higher capacity plants.

3. Power requirements of circulating pump and air pump are much less.

Select the correct answer using the code given below:

A)

1 and 2 only

B)

2 and 3 only

C)

1 and 3 only

D)

1, 2 and 3

View Solution

107)

Consider the following statements:

1. Reheating in a steam power plant leads to increased condenser requirement.

2 The efficiency of regenerative cycle in a steam power plan is maximum when the temperature of bled steam is equal to the geometric mean of the extreme temperatures of the primary flow cycle.

Which of the statements given above is/are correct?

A)

1 only

B)

2 only

C)

Both 1 and 2

D)

neither 1 nor 2

View Solution

108)

Consider the following statements:

1. In a steam power plan, the volume flow at the low pressure end is considerably reduced by bleeding.

2. Theoretically, the efficiency of a steam power plant increases with the increasing number of feed heaters but the gain is in diminishing return.

Which of the statements given above is/are correct?

A)

1 only

B)

2 only

C)

Both 1 and 2

D)

neither 1 nor 2

View Solution

109)

Entropy of a saturated liquid at \[227{}^\circ C\] is 2.6 kJ/kg K. Its latent heat of vaporization is 1800 kJ/kg: then the entropy of saturated vapor at \[227{}^\circ C\] would be:

A)

2.88 kJ/kg K

B)

6.2 kJ/kg K

C)

7.93 kJ/kg K

D)

10.53 kJ/kg K

View Solution

110)

Which of the following statements are true about CANDU reactors?

1. Fuel elements contain natural-uranium dioxide

2. Pressurized heavy-water coolant is used

3. Horizontal pressure tube is used

A)

1 and 2 only

B)

1 and 3 only

C)

2 and 3 only

D)

1, 2 and 3

View Solution

111)

When inspection doors on the wails of boilers are opened, flame does not leap out because:

A)

These holes are small

B)

Pressure inside is negative

C)

Flame travels always in the direction of flow

D)

These holes are located beyond the furnace

View Solution

112)

An induced draft fan is normally located at the:

A)

Outlet of the steam generator before the dust collector

B)

Outlet of the steam generator after the dust collector

C)

Inlet of the steam generator before the air heater

D)

Inlet of the steam generator after the air heater

View Solution

113)

The boiler used in the Nuclear Station at Tarapor is of the:

A)

Pressurized water type

B)

Boiling water type

C)

Gas cooled type

D)

Liquid metal cooled type

View Solution

114)

Consider the following statements:

1. Breeder reactor produces more plutonium than what it consumes.

2. Zirconium is used as a shield material.

3. Lead is the commonly used moderator.

Of these, the ones which are not correct will include:

A)

1, 2 and 3

B)

1 and 2

C)

2 and 3

D)

1 and 3

View Solution

115)

Which one of the following groups of devices are used for part recovery of heat from the flue gases leaving the tube banks in a water tube boiler?

A)

Drum internals, super heaters and economiser

B)

Economiser, air preheater and electrostatic precipitator

C)

Water wall, drum internals and super heaters

D)

Super heaters, economiser and air preheater

View Solution

116)

In large power boilers, soot blowers are used at regular intervals for cleaning the tubes. What is the fluid used for the same?

A)

Low pressure steam

B)

Hot gases

C)

Hot air

D)

Boiling water

View Solution

117)

In high pressure water tube boilers, the tube bundles are:

A)

Hung from top girders

B)

Supported on brick walls

C)

Bolted on steel structures

D)

Firmly fixed on any structure

View Solution

118)

Consider the following statements:

1. Actual mass flow rate of steam will be less than the theoretical value in all cases of flow through a nozzle

2. Mass flow of steam cannot be increased beyond a certain value in the case of flow through a nozzle.

3. Actual velocity of steam at the exit of a nozzle will always be less than the theoretical value.

Of these statements:

A)

1, 2 and 3 are correct

B)

1 and 2 are correct

C)

2 and 3 are correct

D)

1 and 4 are correct

View Solution

119)

If in an impulse turbine designed for free vortex flow, the tangential velocity of steam at the root radius of 250 mm is 430 m/s and the Made height is 100 mm, then the tangential velocity of steam at the tip will be:

A)

602 m/s

B)

504 m/s

C)

409 m/s

D)

307 m/s

View Solution

120)

If in a steam turbine stage, heat drop in moving blade ling is 40 kJ/kg and that in the fixed blade ring is 60 kJ/kg, then the degree of reaction is:

A)

20%

B)

40%

C)

68%

D)

70%

View Solution

121)

High energy rate forming process used for forming components from thin metal sheets or deform thin tubes is:

A)

Petro-forming

B)

Magnetic pulse forming

C)

Explosive forming

D)

Electro-hydraulic forming

View Solution

122)

In the 3-2-1 principle of fixture design, 3 refers to number of:

A)

Set ups possible

B)

Clamps required

C)

Positions on primary face

D)

Locating positions

View Solution

123)

The optimum cutting speed is one which should have:

1. High metal removal rate

2. High cutting tool life

3. Balance the metal removal rate and cutting tool life.

A)

2 and 3

B)

1 and 2 only

C)

2 and 3 only

D)

3 only

View Solution

124)

Satellite is a non-ferrous cast alloy composed of:

A)

Cobalt, chromium and tungsten

B)

Tungsten, vanadium and chromium

C)

Molybdenum, tungsten and chromium

D)

Tungsten, molybdenum, chromium- vanadium

View Solution

125)

External threads can be produced by:

1. Rolling

2. Grinding

3. Milling

A)

1 and 3 only

B)

1 and 2 only

C)

2 and 3 only

D)

1, 2 and 3

View Solution

Railways NTPC (Technical Ability) Power Plant Engineering Question Bank

done Power Plant Engineering Total Questions - 125

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Questions - Power Plant Engineering

Power Plant Engineering Total Questions - 125