Question: Sulphur content of fuels is very important to the plant operators because it____________________?

• 1. has high heating value
• 2. retards electric precipitation
• 3. promotes complete combustion
• 4. has highly corrosive effect

Question: An economiser in a boiler______________________?

• 1. increases steam pressure
• 2. increases steam flow
• 3. decreases fuel consumption
• 4. decreases steam pressure

Question: Spontaneous combustion is a phenomenon in which____________________?

• 1. all the fuel burns instantaneously producing high energy release
• 2. fuel burns with less air
• 3. coal bursts into flame without any external ignition source but by itself due to gradual increase in temperature as a result of heat released by combination of oxygen with coal
• 4. explosion in furnace

Question: Which device is used in thermal power plants to reduce level of pollution___________________?

• 1. induced draft fan
• 2. smoke meter
• 3. chimney
• 4. precipitator

Question: The maximum discharge through a chimney occurs when the height of chimney is_____________________?

• 1. infinitely long
• 2. around 200 meters
• 3. equal to the height of the hot gas column producing draught
• 4. outside temperature is very low

Question: Vacuum for reciprocating steam engines compared to steam turbines is__________________?

• 1. more
• 2. equal
• 3. less
• 4. could be more or less depending on the size of plant

Question: The height of chimney in a power plant is governed by__________________?

• 1. the draft to be created
• 2. limitation of construction facilities
• 3. control of pollution
• 4. quantity of flue gases to be handled

Question: The function of injector used in small capacity boilers is to____________________?

• 1. create vacuum
• 2. inject chemical solution in feed pump
• 3. pump water, similar to boiler feed pump
• 4. add make up water in the system

Question: In designing air preheater, the important design consideration is that_________________?

• 1. approach temperature should be as low as possible
• 2. handling and maintenance should be easier
• 3. heat transfer area should be optimum
• 4. stack gases should not be cooled to the dew point

Question: The temperature of flue gases at air heater outlet should be__________________?

• 1. 100°C
• 2. above dew-point temperature of flue gases
• 3. below dew-point temperature of flue gases
• 4. less than wet bulb temperature of flue gases