Questions and answers for exam Preparation

MCQs

Total Questions : 1935 | Page 8 of 194 pages

Question 71. In accelerated circulation type boiler

Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
Feed pump is employed to supplement natural circulation in water wall type furnace
Water is converted into steam in one pass without any recirculation

Discuss Question

Answer: Option B. -> Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam

Question 72. In forced circulation type boiler

Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
Feed pump is employed to supplement natural circulation in water wall type furnace
Water is converted into steam in one pass without any recirculation

Discuss Question

Answer: Option D. -> Water is converted into steam in one pass without any recirculation

Question 73. Heating of dry steam above saturation temperature is known as

Enthalpy
Superheating
Super saturation
Latent heat

Discuss Question

Answer: Option B. -> Superheating

Question 74. The chimney draught varies with

Climatic conditions
Temperature of furnace gases
Height of chimney
All of these

Discuss Question

Answer: Option D. -> All of these

Question 75. De-Laval turbine is a

Simple impulse turbine
Simple reaction turbine
Impulse-reaction turbine
None of these

Discuss Question

Answer: Option A. -> Simple impulse turbine

Question 76. The efficiency of steam turbines may be improved by

Reheating of steam
Regenerative feed heating
Binary vapor plant
Any one of these

Discuss Question

Answer: Option D. -> Any one of these

Question 77. Green coal, in order to be burnt, must be

Heated sufficiently
Burnt in excess air
Heated to its ignition point
Burnt as powder

Discuss Question

Answer: Option C. -> Heated to its ignition point

Question 78. Incomplete combustion can be best judged by

Smoky chimney exit
Excess air in flue gases
Measuring carbon monoxide in flue gases
Measuring temperature of flue gases at exit of furnace

Discuss Question

Answer: Option C. -> Measuring carbon monoxide in flue gases

Question 79. Blow off cock in a boiler is used to

Control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required
Empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler
Put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit
Increase the temperature of saturated steam without raising its pressure

Discuss Question

Answer: Option B. -> Empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler

Question 80. The factor of evaporation for all boilers is always