Power plant Multiple Choice Questions and Answers

 Power plant Multiple Choice Questions and Answers

Superheaters and Reheaters Control Multiple Choice Questions and Answers


1. Lancashire boiler has _____ internal flue tubes.

a) 1

b) 3

c) 2

d) 4

Answer: 2


2. The number of fire tubes in a Cochran boiler are ___________

a) 75

b) 165

c) 225

d) 175

Answer: 165


3. The diameter of a cylindrical shell of a Scotch marine boiler varies from ___________

a) 3.5 to 4.5m

b) 1.5 to 2m

c) 2.5 to 3.5m

d) none of the mentioned

Answer: 2.5 to 3.5m


4. An economiser is installed in a boiler primarily to ___________

a) increase steam pressure

b) reduce fuel consumption

c) superheat the steam

d) all of the mentioned

Answer: reduce fuel consumption


5. Which of the following is a water tube boiler?

a) Lancashire boiler

b) Cochran boiler

c) Babcock & Wilcox boiler

d) Locomotive boiler

Answer: Babcock & Wilcox boiler


6. The theoretical indicator diagram of a simple steam engine is based upon the assumption that ___________

a) there is no pressure drop due to condensation

b) steam is admitted at boiler pressure & exhausted at condenser pressure

c) the expansion of the steam is hyperbolic

d) all of the mentioned

Answer: all of the mentioned


7. The actual power supplied by the engine crankshaft is called?

a) indicated power

b) frictional power

c) brake power

d) none of the mentioned

Answer: brake power


7. Cut-off ratio is the ratio of?

a) cut-off volume to clearance volume

b) clearance volume to cut-off volume

c) volume at cut-off to swept volume

d) swept volume to volume at cut-off

Answer: volume at cut-off to swept volume


8. A closed vessel made of steel & used for the generation of steam is called a ___________

a) steam condenser

b) steam boiler

c) steam injector

d) steam turbine

Answer: steam boiler


9. The chimney draught varies with?

a) climatic conditions

b) temperature of furnace gases

c) height of chimney

d) all of the mentioned

Answer: all of the mentioned


10. The missing quantity per stroke is equal to?

a) cylinder feed + indicated mass of steam

b) cylinder feed + indicated mass of steam

c) mass of cushion steam + indicated mass of steam

d) mass of cushion steam + cylinder feed

Answer: cylinder feed + indicated mass of steam


11. The equivalent evaporation is defined as?

a) the ratio of heat actually used in producing the steam to the heat liberated in the furnace

b) the amount of water evaporated or steam produced in kg of fuel burnt

c) the amount of water evaporated from ad at 100 degree C into dry & saturated steam

d) none of the mentioned

Answer: the amount of water evaporated from and at 100 degree C into dry & saturated steam


12. When steam after doing work in the cylinder passes into a condenser, the engine is said to be a ___________

a) slow speed engine

b) vertical steam engine

c) condensing steam engine

d) no-condensing steam engine

Answer: condensing steam engine


13. Locomotive boiler is a ___________

a) single tube, vertical, externally fired & stationary boiler

b) single tube, horizontal, internally fired& stationary boiler

c) multitubular, horizontal, externally fired & stationary boiler

d) multitubular, horizontal, internally fired & mobile boiler

Answer: multitubular, horizontal, internally fired & mobile boiler


14. The diagram factor is the ratio of ___________

a) area of actual indicator diagram to the area of theoretical indicator diagram

b) actual work done per stroke to the theoretical work done per stroke

c) actual mean effective pressure to the theoretical mean effective pressure

d) any of the above mentioned

Answer: any of the above mentioned


15. The purpose of superheater in a boiler is

a) to increase the temperature of saturated steam with increase in its pressure

b) to increase the temperature of saturated steam without increase in its pressure

c) to increase the temperature of feedwater for better efficiency

d) none of the above

Answer: to increase the temperature of saturated steam without increase in its pressure


Feedwater Heaters Multiple Choice Questions and Answers 

1. The number of pumps required by a closed heater for pumping the main feedwater stream is?

a) 1

b) 2

c) 3

d) 4

Answer: 1


2. The value of TTD varies with __________

a) heater pressure

b) heater temperature

c) turbine inlet temperature

d) independent of all mentioned

Answer: heater pressure


3. If terminal temperature difference (TTD) is too small, what will be its impact on plant efficiency?

a) it increases

b) it decreases

c) it remains same

d) none of the mentioned

Answer: it increases


4. Expand TTD?

a) turbine temperature difference

b) total temperature difference

c) terminal temperature difference

d) turbine terminal difference

Answer: terminal temperature difference


5. Which of these is the correct expression for terminal temperature difference(TTD)?

a) TTD = saturation temperature of ‘bled’ steam – exit water temperature

b) TTD = saturation temperature of ‘bled’ steam + exit water temperature

c) TTD = saturation temperature of ‘bled’ steam x exit water temperature

d) TTD = saturation temperature of ‘bled’ steam / exit water temperature

Answer: TTD = saturation temperature of ‘bled’ steam – exit water temperature


6. Feedwater heaters are of two types, they are ____________

a) natural and forced

b) saturated and non saturated

c) open and close

d) water driven and steam driven

Answer: open and close


7. Closed heaters are also called __________

a) contact type heater

b) shell and heat exchanger

c) drip heaters

d) shell and tube heater

Answer: shell and heat exchanger


8. Closed heaters are __________

a) horizontal

b) vertical

c) inclined

d) depends on the requirement

Answer: depends on the requirement


9. Why at least one open heater is used?

a) installed vertically

b) feedwater deaeration

c) less cost

d) increase efficiency

Answer: feedwater deaeration


10. In open feedwater heater __________

a) the extracted steam is allowed to mix with feedwater

b) feedwater flows through tubes and steam is condensed outside

c) steam flows outside tubes and feedwater inside

d) steam flows inside tubes and outside inside

Answer: the extracted steam is allowed to mix with feedwater


11. What are the advantages of open heater?

a) lower cost

b) high heat transfer capacity

c) high feedwater temperature

d) all of the mentioned

Answer: all of the mentioned


12. What do you mean by heater drip?

a) condensate

b) heater failure

c) extract

d) maximum temperature

Answer: condensate


13. Feed water heaters are of how many types?

a) One

b) Two

c) Three

d) Four

Answer: Two


14. Which of the following material can be used as a moderator?

a) Beryllium

b) Graphite

c) Heavy water

d) All of the mentioned

Answer: All of the mentioned


15. What is the other name of the open heater?

a) shell & tube heat exchangers

b) contact type heaters

c) regenerative heat exchangers

d) closed heaters

Answer: contact type heaters


16. What is the condition of the fluids in closed heaters?

a) they are separate

b) they are mixed

c) they are partially mixed

d) none of the mentioned

Answer: they are separate


17. What is the other name of the condensate obtained after condensation in a shell-and-tube heat exchanger type closed heaters?

a) Heater rise

b) Heater fall

c) Heater drip

d) None of the mentioned

Answer: Heater drip


18. Why are closed heaters sometimes made vertical?

a) to reduce weight of heaters

b) to reduce floor areas for installations

c) to minimize losses due to weight

d) none of the mentioned

Answer: to reduce floor areas for installations


19. When is a drain-cooler used?

a) when the extracted steam upon condensation gets subcooled

b) when the extracted steam upon subcooling gets condensed

c) the extracted stream has no dependence on drain-cooler

d) none of the mentioned

Answer: when the extracted steam upon condensation gets subcooled


20. Which of the following is not an advantage of an open heater?

a) simplicity

b) lower cost

c) high heat transfer capacity

d) necessity of a pump at each heater to handle the large feedwater stream

Answer: necessity of a pump at each heater to handle the large feedwater stream


21. Which of these is a disadvantage of open heater?

a) simplicity

b) lower cost

c) high heat transfer capacity

d) none of the mentioned

Answer: none of the mentioned


22. What is the purpose of using open heaters in steam power plants?

a) feedwater purification

b) feedwater esterification

c) feedwater deaeration

d) feedwater carbonisation

Answer: feedwater deaeration


23. Closed heaters are ______________ heat exchangers.

a) parallel flow

b) shell-and-tube

c) counter flow

d) cross- flow

Answer: shell-and-tube


24. If plant efficiency is high, what will be its effect on heater size?

a) it remains same

b) it increases

c) it decreases

d) none of the mentioned

Answer: it increases


25. What is the function of the trap applied to the condensate?

a) the trap stops the condensate fully

b) the trap stops only vapour & allows liquid to pass through it

c) the trap stops only liquid & allows vapour to pass through it

d) none of the mentioned

Answer: the trap stops only vapour & allows liquid to pass through it


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