Question: For forced draught system, the function of chimney is mainly_____________?

• 1. to produce draught to accelerate the combustion of fuel
• 2. to discharge gases high up in the atmosphere to avoid hazard
• 3. to reduce the temperature of the hot gases discharged
• 4. none of the above

Question: The draught produced by steel chimney as compared to that produced by brick chimney for the same height is_____________?

• 1. less
• 2. more
• 3. same
• 4. may be more or less

Question: The draught produced by chimney of given height at given outside temperature___________?

• 1. decreases if the chimney gas temperature increases
• 2. increases if the chimney gas temperature increases
• 3. remains same irrespective of chimney gas temperature
• 4. may increase or decrease

Question: The draught produced, for a given height of the chimney and given mean temperature of chimney gases_______________?

• 1. decreases with increase in outside air temperature
• 2. increases with increase in outside air temperature
• 3. remains the same irrespective of outside air temperature
• 4. may increase or decrease with increase in outside air temperature

Question: In a boiler installation the natural draught is produced_____________?

• 1. due to the fact that furnace gases being light go through the chimney giving place to cold air from outside to rush in
• 2. due to the fact that pressure at the grate due to cold column is higher than the pressure at the chimney base due to hot column
• 3. due to the fact that at the chimney top the pressure is more than its environmental pressure
• 4. all of the above

Question: The draught which a chimney produces is called_____________?

• 1. induced draught
• 2. natural draught
• 3. forced draught
• 4. balanced draught

Question: The modern steam turbines are___________?

• 1. impulse turbines
• 2. reaction turbines
• 3. impulse-reaction turbines
• 4. none of the above

Question: Economiser is used to heat_____________?

• 1. air
• 2. feed water
• 3. flue gases
• 4. all above

Question: Mercury is a choice with steam in binary vapour cycle because it has____________?

• 1. higher critical temperature and pressure
• 2. higher saturation temperature than other fluids
• 3. relatively low vapourisation pressure
• 4. all above

Question: Reheat cycle in steam power plant is used to________________?

• 1. utilise heat of flue gases
• 2. increase thermal efficiency
• 3. improve condenser performance
• 4. reduce loss of heat