250+ TOP MCQs on Boilers – Boiling and Equipment and Answers

Heat Transfer Operations Multiple Choice Questions on “Boilers – Boiling and Equipment”.

1. Which one of the following boilers can be classified as one of the following based on the position of water and hot gasses?
a) Fire Tube
b) Natural Convection
c) External fired
d) Internal fired

Answer: a
Clarification: Fire tube is a classification based on position of the constituting elements whereas natural convection and forced ones are based on circulation type.

2. Which one of the following is not a classification of boilers?
a) Fire tube and Water tube
b) Feed type
c) Pressure
d) Circulation

Answer: b
Clarification: The boilers are usually not classified as feed type rather the common classifications are tube-type, circulation, internal/external fired etc.

3. Furnace type boilers can be classified as Single/ Dual furnace type boilers.
a) True
b) False

Answer: a
Clarification: Yes the statement is true, the two classes of furnace type boilers are single and double/dual furnace type boilers.

4. There are two types of water feeding in a boiler, they are ________ and _________
a) Open feed System and Closed feed system
b) Condensed and Raw
c) Feed-water and clean water
d) Hot and cold water

Answer: a
Clarification: The two classifications are Open feed System and Closed feed system where in open feed the water is in direct contact and in closed feed it is not in direct contact.

5. In a fire tube boiler, the water to be heated is kept in the ________
a) Tubes of the setup
b) Shell of the setup with hot gas in tubes
c) Tank with a fire chamber that conducts heat by steel rods
d) Tank and heated by fire below it

Answer: b
Clarification: In a fire tube boiler, the water to be heated is kept in the shells and the furnace can be situated at one end of a fire-tube which lengthens the path of the hot gases, thus increasing the heating surface which increases to further extent by making the gases reverse direction through a second parallel tube.

6. Fire-tube boilers usually have a comparatively ________ rate of steam production, and ______ steam storage capacity.
a) Low, High
b) High, Low
c) Low, Low
d) High, High

Answer: a
Clarification: Fire tubes are equipped with large storage tanks heated from below hence these have high steam storage capacity.

7. In water tube boilers, the flue gases/ the heating gases are passed through the __________ of the setup.
a) Outer surface of the tank
b) Tubes of the setup
c) Covering shell
d) Chamber inside the water tank

Answer: c
Clarification: The water is kept in the tubes because the water undergoes expansion which leads to large pressure in the setup which is more efficiently handled by the tubes, hence it is kept in tubes and heating gases are passed through the shell.

8. When water is boiled, it releases saturated steam, which one of the following industries cannot use this type of steam?
a) Steam locomotive
b) Food heating
c) Sanitation
d) Cooking

Answer: a
Clarification: Steam locomotives have movable parts and require high energy output, hence using saturated steam does not necessarily produce visible energy production for the heat supplied rather dry superheated steam is best suited for them.

9. Water tube boilers generally give _______ steam production rates, and _______ storage capacity than the fire tubes setup.
a) Low, High
b) High, Low
c) Low, Low
d) High, High

Answer: b
Clarification: In this type of boilers, the tubes are filled with water and are arranged inside a furnace in a number of possible configurations. These water tube boilers have water in the tubes and hence have less volume for water storage due to lack of space yet they are exposed to much larger area for heat transfer.

10. In flash boilers, the water is passed through ________ which are very hot and leads to quick conversion to vapour or flashed to steam.
a) Furnaces
b) Superheated steam
c) Sub-cooled steam
d) Explosives

Answer: a
Clarification: Flash boilers are normally fired by liquid or gaseous fuel because this allows a quick response to changes in the demand for steam. These are very hot and quickly convert the water to steam.

11. The efficiency of the steam plant decreases by using superheated steam plants owing to the increased cost and consumption of fuels.
a) True
b) False

Answer: b
Clarification: The efficiency increases by using superheated steam than saturated steam at the same cost of fuels. Hence the statement is wrong.

12. In a supercritical steam generator, the pressure of the water is kept _________ the critical pressure so that the water becomes directly to steam and rotate turbines for electricity production.
a) Below
b) Above
c) Equal to
d) Much below

Answer: b
Clarification: At pressure above the critical point of the water, it allows the water to coexist in its two phases as gas and water which when exposed gets totally converted to steam.