How is a high-pressure boiler classified?

When velocity of water is very low

When it operates, high amount of steam is required for the operation of the cycle

Conventionally, in a Babcock-Wilcox boiler, the circulation of water between the drum and the water-tubes is:

There is no circulation of water

Normally by naturally circulation (thermosiphon)

For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has:

Heating surface depends on other parameters

In power plant, function of air pre heater is:

to raise temperature of feed water

to raise temperature of entering air

to raise temperature of feed water

to increase temperature of steam

Identify the requirement of a good boiler from the following options.

It should use maximum refractory material.

it should be able to produce steam at minimum pressure.

It should have more flexible joints.

It should be light in weight and compact.

An economizer in a steam generator performs the function of preheating the

Combustion air as well as input fuel

Determine the correctness or otherwise of the following Assertion [a] and the Reason [r].Assertion [a]: In a power plant working on a Ranking cycle, the regenerative feed water heating improves the efficiency of the steam turbine.Reason [r]: The regenerative feed water heating raises the average temperature of heat addition in the Rankine cycle.

Both [a] and [r] are true but [r] is NOT the correct reason for [a].

Both [a] and [r] are true and [r] is the correct reason for [a].

Both [a] and [r] are true but [r] is NOT the correct reason for [a].

A super critical boiler consists of only economizer and superheater and it does not have an evaporator because

Flue gas used to run rotary compressor supply high pressure air to the furnace

Water temperature can be raised to critical temperature in the economizer itself

High evaporation rate is achieved through forced circulation of water through tubes

Enthalpy of evaporation becomes zero at critical pressure or above that

Flue gas used to run rotary compressor supply high pressure air to the furnace

In a glass tube type, water level indicator for a boiler one end of the tube is connected to water space and the other end is connected to

Super heated steam outlet from super heater

84 + Mcqs in Function Boilers in Energy Engineering Page 1 McqOptions

1.	How is a high-pressure boiler classified?
A.	When pressure > 50 bar
B.	When pressure > 80 bar
C.	When velocity of water is very low
D.	When it operates, high amount of steam is required for the operation of the cycle
Answer» C. When velocity of water is very low

Discussion

2.	In a boiler, one or more plates are bent into a cylindrical form and riveted or welded together. This is called:
A.	grate
B.	mountings
C.	shell
D.	refractory
Answer» D. refractory

Discussion

3.	Pick the correct example of a fire-tube boiler.
A.	Wilcox
B.	La-Mont
C.	Benson
D.	Cochran
Answer» E.

Discussion

4.	In a boiler, feed water supplied per hour is 205 kg while coal fired per hour is 23 kg. The net enthalpy rise per kg of water is 145 kJ. If the calorific value of coal is 2050 kJ/kg, then boiler efficiency will be
A.	56%
B.	75%
C.	48%
D.	63%
Answer» E.

Discussion

5.	Draught is produced in a locomotive boiler by:
A.	steam jet
B.	critical fan
C.	chimney
D.	locomotion
Answer» B. critical fan

Discussion

6.	Biggest loss in the boiler is:
A.	Dryness in flue gasses
B.	Steam formation
C.	Unburnt carbon
D.	Moisture in fuel
Answer» B. Steam formation

Discussion

7.	Benson boilers have ______ water drum(s).
A.	zero
B.	two
C.	three
D.	one
Answer» B. two

Discussion

8.	Maximum heat is lost in a boiler due to
A.	Unburnt carbon
B.	Flue gases
C.	Incomplete combustion
D.	Moisture in fuel
Answer» C. Incomplete combustion

Discussion

9.	______ CANNOT be counted as boiler mounting.
A.	Blow-off cock
B.	Feed water pump
C.	Fusible plug
D.	Stop valve
Answer» C. Fusible plug

Discussion

10.	A portion of water is discharged when the boiler is in operation to blow out mud scale or sediments periodically, by a:
A.	feed check valve
B.	blow off cock
C.	safety valve
D.	fusible plug
Answer» C. safety valve

Discussion

11.	In a steam generator, the feed water supply rate is 205 kg/h, and the rate of coal-fired is 23 kg/h. The net enthalpy rise of water for conversion to steam is 145 kJ/kg. If the calorific value of coal is 2050 kJ/kg, the steam generator efficiency will approximately be:
A.	42%
B.	72%
C.	52%
D.	62%
Answer» E.

Discussion

12.	______ falls under the category of a water tube boiler.
A.	Locomotive boiler
B.	Cornish boiler
C.	LaMont boiler
D.	Lancashire boiler
Answer» D. Lancashire boiler

Discussion

13.	In a boiler, the platform in the furnace upon which fuel is burnt and is made of cast iron bars, is the:
A.	grate
B.	shell
C.	furnace
D.	mountings
Answer» B. shell

Discussion

14.	Due to the turbidity of the water in the boiler feedwater, _____ is caused.
A.	sludge
B.	embrittlement
C.	corrosion
D.	cracking
Answer» B. embrittlement

Discussion

15.	Equivalent evaporation of a boiler is defined with respect to generation of steam from & at _______.
A.	20°C
B.	100°C
C.	150°C
D.	Any of these
Answer» C. 150°C

Discussion

16.	Conventionally, in a Babcock-Wilcox boiler, the circulation of water between the drum and the water-tubes is:
A.	Caused by gravity
B.	By a pump
C.	There is no circulation of water
D.	Normally by naturally circulation (thermosiphon)
Answer» E.

Discussion

17.	For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has:
A.	More heating surface
B.	Less heating surface
C.	Equal heating surface
D.	Heating surface depends on other parameters
Answer» B. Less heating surface

Discussion

18.	___________ is the platform in a furnace upon which fuel is burnt.
A.	Grate
B.	Accessory
C.	Blowoff cock
D.	Shell
Answer» B. Accessory

Discussion

19.	A closed vessel in which steam is produced from water by combustion of fuel is called a:
A.	nozzle
B.	turbine
C.	compressor
D.	boiler
Answer» E.

Discussion

20.	If mw is the mass of water changing the enthalpy from h1 and h2 in a boiler and L is the latent heat of steam at 100°C, then the equivalent evaporation is defined as:
A.	[mw (h2 – h1)]/L
B.	[mw (h2 + h1)]/L
C.	[mw (h2 + L)]/h1
D.	(mwh1h2)/L
Answer» B. [mw (h2 + h1)]/L

Discussion

21.	In a fire tube boiler, the operating pressure range is:
A.	30 to 35 bar
B.	26 to 29 bar
C.	21 to 25 bar
D.	16 to 20 bar
Answer» E.

Discussion

22.	Name the boiler which can generate superheated steam without additional accessories.
A.	Cornish boiler
B.	Locomotive boiler
C.	Lancashire boiler
D.	Cochran boiler
Answer» D. Cochran boiler

Discussion

23.	At critical point the enthalpy of vaporization is
A.	Dependent of temperature only
B.	Maximum
C.	Minimum
D.	Zero
Answer» E.

Discussion

24.	A boiler produces 1000 kg/hr steam with rise in enthalpy of steam of 2500 kJ/kg. The calorific value of coal used is 30000 kJ/kg and its consumption is 100 kg/hr. What would be the boiler efficiency?
A.	18.33%
B.	73.33%
C.	8.33%
D.	83.33%
Answer» E.

Discussion

25.	In a boiler, the device in which the waste heat of flue gases is utilised for heating feed water is called a/an:
A.	economiser
B.	superheater
C.	air preheater
D.	injector
Answer» B. superheater

Discussion

26.	Foaming is a phenomenon that occurs in the boiler feed water due to______
A.	manganese
B.	sodium chloride
C.	oil
D.	nitrogen peroxide
Answer» D. nitrogen peroxide

Discussion

27.	In Lancashire boilers, the feed water tube is:
A.	open channel type
B.	perforated
C.	thin conduit
D.	solid
Answer» C. thin conduit

Discussion

28.	In power plant, function of air pre heater is:
A.	to avoid hazard
B.	to raise temperature of entering air
C.	to raise temperature of feed water
D.	to increase temperature of steam
Answer» C. to raise temperature of feed water

Discussion

29.	A project initially costs Rs. 5,000 and generates year-end cash inflows of Rs. 1800, Rs. 1600, Rs. 1400, Rs. 1200 and Rs. 1000 respectively in five years of its life. If the rate of return is 10%, the net present value (NPV) will be
A.	Rs. 500
B.	Rs. 450
C.	Rs. 400
D.	Rs. 350
Answer» C. Rs. 400

Discussion

30.	________ boiler is an example of once-through boilers.
A.	Benson
B.	La-Mont
C.	Benson and La-Mont
D.	Loeffler
Answer» B. La-Mont

Discussion

31.	A boiler produces 9 kg steam/kg of coal burnt, which has a calorific value of 27 MJ/kg. The enthalpy of feed water and steam at the exit are 300 kJ/kg and 3000 kJ/kg respectively. Its thermal efficiency is:
A.	90%
B.	83.57%
C.	55%
D.	94.2%
Answer» B. 83.57%

Discussion

32.	Identify the requirement of a good boiler from the following options.
A.	It should use maximum refractory material.
B.	it should be able to produce steam at minimum pressure.
C.	It should have more flexible joints.
D.	It should be light in weight and compact.
Answer» E.

Discussion

33.	An economizer in a steam generator performs the function of preheating the
A.	Combustion air
B.	Feed water
C.	Input fuel
D.	Combustion air as well as input fuel
Answer» C. Input fuel

Discussion

34.	_____ boiler involves circulation of water by natural convention.
A.	Babcock-Wilcox
B.	Benson
C.	Velox
D.	LaMont
Answer» B. Benson

Discussion

35.	Fusible plug is used in a boiler to/for:
A.	extinguish the fire
B.	preheat the steam
C.	discharge excess water
D.	superheating the steam
Answer» B. preheat the steam

Discussion

36.	In a LaMont boiler, the mass flow rate of water through the boiler circulation pump, compared to the rate of evaporation of water, is typically:
A.	twenty-five times
B.	forty times
C.	ten times
D.	thirty times
Answer» D. thirty times

Discussion

37.	______ is NOT a water tube boiler.
A.	Stirling boiler
B.	Scotch Marine boiler
C.	Babcock-Wilcox boiler
D.	Benson boiler
Answer» C. Babcock-Wilcox boiler

Discussion

38.	Determine the correctness or otherwise of the following Assertion [a] and the Reason [r].Assertion [a]: In a power plant working on a Ranking cycle, the regenerative feed water heating improves the efficiency of the steam turbine.Reason [r]: The regenerative feed water heating raises the average temperature of heat addition in the Rankine cycle.
A.	Both [a] and [r] are true and [r] is the correct reason for [a].
B.	Both [a] and [r] are true but [r] is NOT the correct reason for [a].
C.	Both [a] and [r] are false
D.	[a] is false and [r] is true.
Answer» B. Both [a] and [r] are true but [r] is NOT the correct reason for [a].

Discussion

39.	If the circulation of water in a boiler is made by pump, then it is known as
A.	Natural circulation boiler
B.	Forced circulation boiler
C.	Internally fired boiler
D.	Externally fired boiler
Answer» C. Internally fired boiler

Discussion

40.	A device used to put off fire in the furnace of the boiler when the level of the water in the boiler falls to an unsafe limit is called:
A.	Blow of cock
B.	Economiser
C.	Fusible plug
D.	Superheated
Answer» D. Superheated

Discussion

41.	A super critical boiler consists of only economizer and superheater and it does not have an evaporator because
A.	Water temperature can be raised to critical temperature in the economizer itself
B.	High evaporation rate is achieved through forced circulation of water through tubes
C.	Enthalpy of evaporation becomes zero at critical pressure or above that
D.	Flue gas used to run rotary compressor supply high pressure air to the furnace
Answer» D. Flue gas used to run rotary compressor supply high pressure air to the furnace

Discussion

42.	As per regulations boilers should be fitted with ________ safety valves.
A.	two
B.	three
C.	four
D.	five
Answer» B. three

Discussion

43.	A boiler is having a chimney of 35 m height. The draught produced in terms of water column is 20 mm. The temperature of flue gas inside the chimney is 365°C and that of air outside the chimney is 32°C. The mass of air used will be nearly
A.	10.3 kg/kg of fuel
B.	12.5 kg/kg of fuel
C.	14.7 kg/kg of fuel
D.	16.9 kg/kg of fuel
Answer» E.

Discussion

44.	Balanced draught system uses
A.	steam jet draught
B.	induced draught
C.	forced draught
D.	both induced and force draught
Answer» E.

Discussion

45.	A fusible plug must be used primarily for safety purposes in which of the following types of boilers?
A.	Oil-fired boiler
B.	High-pressure boiler
C.	Fire-tube boiler
D.	Marine type boiler
Answer» C. Fire-tube boiler

Discussion

46.	In a glass tube type, water level indicator for a boiler one end of the tube is connected to water space and the other end is connected to
A.	Chimney
B.	Super heated steam outlet from super heater
C.	Steam space in drum
D.	Water space also
Answer» C. Steam space in drum

Discussion

47.	_________ boiler is capable of generating a small quantity of steam per unit time at high pressure.
A.	Babcock-Wilcox
B.	Scottish marine
C.	Locomotive
D.	Lancashire
Answer» B. Scottish marine

Discussion

48.	Inside a boiler surface, scales are formed due to the presence of ____ in the boiler feedwater.
A.	insoluble compounds
B.	Ca and Mg salts
C.	oils
D.	dissolved gases
Answer» C. oils

Discussion

49.	Locomotive boiler produces steam at
A.	Medium rate
B.	Low rate
C.	Very high rate
D.	Very low rate
Answer» D. Very low rate

Discussion

50.	A boiler accessory that is used to put off the fire in the furnace of the boiler when the water level in the boiler falls below a safe level and prevent overheating of tubes
A.	Feed check valve
B.	Blow-off cock
C.	Fusible plug
D.	Steam stop valve
Answer» D. Steam stop valve

Discussion

Explore topic-wise MCQs in Energy Engineering.

How is a high-pressure boiler classified?

In a boiler, one or more plates are bent into a cylindrical form and riveted or welded together. This is called:

Pick the correct example of a fire-tube boiler.

In a boiler, feed water supplied per hour is 205 kg while coal fired per hour is 23 kg. The net enthalpy rise per kg of water is 145 kJ. If the calorific value of coal is 2050 kJ/kg, then boiler efficiency will be

Draught is produced in a locomotive boiler by:

Biggest loss in the boiler is:

Benson boilers have ______ water drum(s).

Maximum heat is lost in a boiler due to

______ CANNOT be counted as boiler mounting.

A portion of water is discharged when the boiler is in operation to blow out mud scale or sediments periodically, by a:

In a steam generator, the feed water supply rate is 205 kg/h, and the rate of coal-fired is 23 kg/h. The net enthalpy rise of water for conversion to steam is 145 kJ/kg. If the calorific value of coal is 2050 kJ/kg, the steam generator efficiency will approximately be:

______ falls under the category of a water tube boiler.

In a boiler, the platform in the furnace upon which fuel is burnt and is made of cast iron bars, is the:

Due to the turbidity of the water in the boiler feedwater, _____ is caused.

Equivalent evaporation of a boiler is defined with respect to generation of steam from & at _______.

Conventionally, in a Babcock-Wilcox boiler, the circulation of water between the drum and the water-tubes is:

For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has:

___________ is the platform in a furnace upon which fuel is burnt.

A closed vessel in which steam is produced from water by combustion of fuel is called a:

If mw is the mass of water changing the enthalpy from h1 and h2 in a boiler and L is the latent heat of steam at 100°C, then the equivalent evaporation is defined as:

In a fire tube boiler, the operating pressure range is:

Name the boiler which can generate superheated steam without additional accessories.

At critical point the enthalpy of vaporization is

A boiler produces 1000 kg/hr steam with rise in enthalpy of steam of 2500 kJ/kg. The calorific value of coal used is 30000 kJ/kg and its consumption is 100 kg/hr. What would be the boiler efficiency?

In a boiler, the device in which the waste heat of flue gases is utilised for heating feed water is called a/an:

Foaming is a phenomenon that occurs in the boiler feed water due to______

In Lancashire boilers, the feed water tube is:

In power plant, function of air pre heater is:

A project initially costs Rs. 5,000 and generates year-end cash inflows of Rs. 1800, Rs. 1600, Rs. 1400, Rs. 1200 and Rs. 1000 respectively in five years of its life. If the rate of return is 10%, the net present value (NPV) will be

________ boiler is an example of once-through boilers.

A boiler produces 9 kg steam/kg of coal burnt, which has a calorific value of 27 MJ/kg. The enthalpy of feed water and steam at the exit are 300 kJ/kg and 3000 kJ/kg respectively. Its thermal efficiency is:

Identify the requirement of a good boiler from the following options.

An economizer in a steam generator performs the function of preheating the

_____ boiler involves circulation of water by natural convention.

Fusible plug is used in a boiler to/for:

In a LaMont boiler, the mass flow rate of water through the boiler circulation pump, compared to the rate of evaporation of water, is typically:

______ is NOT a water tube boiler.

If the circulation of water in a boiler is made by pump, then it is known as

A device used to put off fire in the furnace of the boiler when the level of the water in the boiler falls to an unsafe limit is called:

A super critical boiler consists of only economizer and superheater and it does not have an evaporator because

As per regulations boilers should be fitted with ________ safety valves.

A boiler is having a chimney of 35 m height. The draught produced in terms of water column is 20 mm. The temperature of flue gas inside the chimney is 365°C and that of air outside the chimney is 32°C. The mass of air used will be nearly

Balanced draught system uses

A fusible plug must be used primarily for safety purposes in which of the following types of boilers?

In a glass tube type, water level indicator for a boiler one end of the tube is connected to water space and the other end is connected to

_________ boiler is capable of generating a small quantity of steam per unit time at high pressure.

Inside a boiler surface, scales are formed due to the presence of ____ in the boiler feedwater.

Locomotive boiler produces steam at

A boiler accessory that is used to put off the fire in the furnace of the boiler when the water level in the boiler falls below a safe level and prevent overheating of tubes