Power Plant Engineering Multiple Choice Questions on “Evaporation, Boiler Blowdown and Steam Purity”.
1. When the circulation of water, in a boiler, is by a centrifugal pump, then the boiler is known as _____________
a) forced circulation boiler
b) externally fired boiler
c) naturally circulation boiler
d) internally fired boiler
Answer: a
Clarification: When the circulation of water, in a boiler, is by a centrifugal pump, then the boiler is known as forced circulation boiler.
2. A single acting steam engine produces __________ power than that of double acting steam engine.
a) equal
b) double
c) half
d) 4 times
Answer: c
Clarification: A single acting steam engine produces half power than that of double acting steam engine.
3. Cut-off governing of steam engines is a method of controlling the engine output by varying __________
a) volume of intake steam
b) pressure of intake steam
c) temperature of intake steam
d) all of the mentioned
Answer: a
Clarification: Cut-off governing of steam engines is a method of controlling the engine output by varying volume of intake steam.
4. A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose is known as __________
a) air preheater
b) superheater
c) injector
d) none of the mentioned
Answer: a
Clarification: A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is knwon as air-preheater.
5. Which of the following statement is correct?
a) Fire tube boilers are internally fired
b) Lancashire boiler is a fire tube boiler
c) Babcock and Wilcox boiler is a water tube boiler
d) All of the mentioned
Answer: d
Clarification: All the mentioned statements are correct.
6. In a uniflow engine __________
a) steam enters and exhausts through the same port
b) steam enters at one end and exhausts at the centre
c) steam enters at the centre and exhausts at the other end
d) none of the mentioned
Answer: b
Clarification: Steam enters at one end and exhausts at the centre in a Uniflow engine.
7. A safety valve mainly used with locomotive and marine boilers is __________
a) lever safety valve
b) dead weight safety valve
c) spring loaded safety valve
d) high steam and low water safety valve
Answer: c
Clarification: A safety valve mainly used with locomotive and marine boilers is spring loaded safety valve.
8. The power of a boiler may be defined as __________
a) the amount of water evaporated or steam produced in kg per kg of fuel burnt
b) the ratio of heat actually used in producing the steam to the heat liberated in the furnace
c) the evaporation of 15.653 kg of water per hour from and at 100° C
d) the amount of water evaporated from and at 100° C into dry and saturated steam
Answer: a
Clarification: The power of a boiler may be defined as the amount of water evaporated or steam produced in kg per kg of fuel burnt.
9. Which of the following boiler is best suited to meet the fluctuating demand of steam?
a) Cornish boiler
b) Lancashire boiler
c) Locomotive boiler
d) Babcock & Wilcox boiler
Answer: c
Clarification: Locomotive Boiler is the best suited to meet the fluctuating demand of steam.
10. The diameter of Cornish boiler varies from __________
a) 1 to 2m
b) 0.5 to 1m
c) 1.25 to 2.5m
d) 2 to 3m
Answer: a
Clarification: The diameter of Cornish Boiler varies from 1-2 m.
11. Besides mean effective pressure, the data required to determine the indicated power of an engine include __________
a) piston diameter, length of stroke and calorific value of fuel
b) piston diameter, specific fuel consumption and Calorific value of fuel
c) piston diameter, length of stroke and speed of rotation
d) specific fuel consumption, speed of rotation and torque
Answer: c
Clarification: Besides mean effective pressure, the data required to determine the indicated power of an engine include piston diameter, length of stroke and speed of rotation.
12. A compound steam engine in which the high pressure and low pressure cylinders have common piston rod is called __________
a) Tandem type compound engine
b) Woolf type compound engine
c) Receiver type compound engine
d) None of the mentioned
Answer: a
Clarification: A compound steam engine in which the high pressure and low pressure cylinders have common piston rod, is called Tandem type compound engine.
13. What is the average operating pressure of Benson boiler?
a) 200 bar
b) 150 bar
c) 250 bar
d) 100 bar
Answer: b
Clarification: The average operating pressure of Benson boiler is 150 bar.
14. What is the function of a safety valve?
a) to indicate the water level inside the boiler to an observer
b) to measure pressure of steam inside the steam boiler
c) to blow off steam when the pressure of steam inside the boiler exceeds the working pressure
d) none of the mentioned
Answer: c
Clarification: The function of a safety valve is to blow off steam when the pressure of steam inside the boiler exceeds the working pressure.
15. What is the rate of steam produced in Benson boiler?
a) 250 tonnes/h
b) 175 tonnes/h
c) 100 tonnes/h
d) 135 tonnes/h
Answer: d
Clarification: The rate of steam produced in Benson boiler is 135 tonnes/h.