With increase in load, convection superheater has :
A. drooping characteristic
B. linear characteristic
C. rising characteristic
D. flat characteristic
C. none of the above
The temperature of flue gases at air heater outlet should be :
A. 100°C
B. above dew-point temperature of flue gases
C. below dew-point temperature
D. less than wet bulb temperature
E. above wet bulb temperature
The function of injector used in small capacity boilers is to :
A. create vacuum
B. inject chemical solution
C. pump water, similar to boiler feed pump
D. add make up water
E. none of the above
The height of chimney in a power plant is governed by :
A. the draft to be created
B. limitation of construction facilities
C. control of pollution
D. quantity of flue gases to be handled
E. all of the above
Vacuum for reciprocating steam engines compared to steam turbines is :
A. more
B. equal
C. less
D. could be more or less depending on the size of plant
E. none of the above
In locomotives, the draught is produced by :
A. chimney
B. induced draft fan
C. both combined A. and B.
D. steam jet draught
E. none of the above
The maximum discharge through a chimney occurs when the height of chimney is :
A. infinitely long
B. around 200 meters
C. equal to the height of the hot gas column producing draught
D. outside temperature is very low
E. more than the tallest building nearby
Which device is used in thermal power plants to reduce level of pollution :
A. induced draft fan
B. smoke meter
C. chimney
D. precipitator
E. pulveriser
Ultimate analysis of fuel is determination of percentage of :
A. carbon, hydrogen, nitrogen, sulphur, moisture
B. fixed carbon, ash, volatile matter, moisture
C. higher calorific value
B. lower calorific value
E. best analysis
Sulphur in coal results in :
A. causing clinkering and slagging
B. corroding air heaters
C. spontaneous combustion
D. facilitating ash precipitation
E. all of the above
Green coal, in order to be burnt, must be :
A. heated sufficiently
B. burnt in excess air
C. heated to its ignition point
D. burnt as powder
E. burnt as lumps
