Questions and answers for exam Preparation

MCQs

Total Questions : 1935 | Page 6 of 194 pages

Question 51. The capacity of induced draft fan compared to forced draft fan in a boiler is

Same
More
Less
Less or more depending on size of boiler

Discuss Question

Answer: Option B. -> More

Question 52. Which of the following statement indicates the difference between Cornish boiler and Lancashire boiler?

Cornish boiler is a water tube boiler whereas Lancashire boiler is a fire tube boiler
Cornish boiler is a fire tube boiler whereas Lancashire boiler is a water tube boiler
Cornish boiler has one flue tube whereas Lancashire boiler has two flue tubes
Cornish boiler has two flue tubes whereas Lancashire boiler has one flue tube

Discuss Question

Answer: Option C. -> Cornish boiler has one flue tube whereas Lancashire boiler has two flue tubes

Question 53. The ratio of the useful heat drop to the isentropic heat drop is called

Condenser efficiency
Nozzle efficiency
Boiler efficiency
Vacuum efficiency

Discuss Question

Answer: Option B. -> Nozzle efficiency

Question 54. In recuperative air preheaters, the heat is transferred

From a metal wall from one medium to another
From heating an intermediate material and then heating the air from this material
By direct mixing
Heat is transferred by bleeding some gases from furnace

Discuss Question

Answer: Option A. -> From a metal wall from one medium to another

Question 55. In regenerative air preheaters, the heat is transferred

From a metal wall from one medium to another
From heating an intermediate material and then heating the air from this material
By direct mixing
Heat is transferred by bleeding some gas from furnace

Discuss Question

Answer: Option B. -> From heating an intermediate material and then heating the air from this material

Question 56. Which of the following statement is wrong?

The factor of evaporation for all boilers is always greater than unity
The amount of water evaporated in kg per kg of fuel burnt is called equivalent evaporation from and at 100° C
The ratio of heat actually used in producing the steam to the heat liberated in the furnace is called boiler efficiency
None of the above

Discuss Question

Answer: Option D. -> None of the above

Question 57. Which of the following statement is wrong?

The critical pressure gives the velocity of steam at the throat equal to the velocity of sound
The flow in the convergent portion of the nozzle is subsonic
The flow in the divergent portion of the nozzle is supersonic
To increase the velocity of steam above sonic velocity (supersonic) by expanding steam below the critical pressure, the divergent portion for the nozzle is not necessary

Discuss Question

Answer: Option D. -> To increase the velocity of steam above sonic velocity (supersonic) by expanding steam below the critical pressure, the divergent portion for the nozzle is not necessary

Question 58. Which of the following statement is wrong?