5. The impurities are removed from boiler with the help of

a. Safety valve b. Blow off cock c. Stop valve d. Fusibleplug

6. Which of the following is used to heat the feed water byusing waste heat of flue gases?

a. Air preheater b. Super heater c. Economizer d. Steamseparator

7. In fire tube boilers, pressure is limited to

a. 16 bar b. 32 bar c. 48 bar d. 64 bar

8. The following is an accessory of a boiler.

a. Pressure gauge b. Safety valve c. Fusible plug d. Superheater

9. The function of an economizer in a steam power plant isto

a. increase the temperature of air supplied to a boiler b.increase the enthalpy of feed water c. condense the exhaust steamfrom the turbine d. heat the fuel before combustion