Practice Test: Question Set - 11
1. In recuperative air preheaters, the heat is transferred
- (A) From a metal wall from one medium to
another
- (B) From heating an
intermediate material and then heating the air from this material
- (C) By direct mixing
- (D) Heat is transferred
by bleeding some gases from furnace
2. The process of draining steam from the turbine, at certain points during its expansion and using this steam for heating the feed water in feed water heaters and then supplying it to the boiler is known as
- (A) Regenerative
heating
- (B) Reheating
of steam
- (C) Bleeding
- (D) None of
these
3. Which of the following statement is wrong?
- (A) The
mechanical draught reduces the height of chimney
- (B) The
natural draught reduces the fuel consumption
- (C) A
balanced draught is a combination of induced and forced draught
- (D) All
of the above
4. Sulphur content of fuels is very important to the plant operators because it
- (A) Has high heating
value
- (B) Retards electric precipitation
- (C) Promotes complete
combustion
- (D) Has highly corrosive
effect
5. Stage efficiency is also known as
- (A) Diagram
efficiency
- (B) Nozzle
efficiency
- (C) Gross
efficiency
- (D) None
of these
6. A device used to heat feed water by utilizing the heat in me exhaust flue gases before leaving through the chimney, is known as
- (A) Economizer
- (B) Fusible
plug
- (C) Superheater
- (D) Stop
valve
7. Which is not correct statement about the function of furnace?
- (A) To provide proper
conditions for continuous complete combustion
- (B) Mix fuel with air and
ignite
- (C) Separate ash from coal
- (D) Maintain heat supply
to prepare and ignite the incoming fuel
8. In a nozzle, whole frictional loss is assumed to occur between
- (A) Inlet and
throat
- (B) Inlet
and outlet
- (C) Throat and
exit
- (D) All
of these
9. The working pressure range for a LaMont boiler is
- (A) 0.5 to 10
MN/m²
- (B) 1 to 15
MN/m²
- (C) 2.5 to 15
MN/m²
- (D) 3.5 to 20
MN/m²
10. The basic job of feed water treatment in boilers is to overcome the problem of
- (A) Corrosion
- (B) Scale
- (C) Carryover
- (D) All of the above
11. In a De-Laval nozzle expanding superheated steam from 10 bar to 0.1 bar, the pressure at the minimum cross-section (i. e. pressure at throat, p₂) will be
- (A) 3.3 bar
- (B) 5.46
bar
- (C) 8.2 bar
- (D) 9.9
bar
12. In a glass tube type water indicator for a boiler, one end of the tube is connected to water space and the other end is connected to
- (A) Water
space also
- (B) Chimney
- (C) Steam
space
- (D) Superheater
13. At very low temperature, the melting and boiling temperatures become equal. This temperature is
- (A) 373°K
- (B) 273.16°K
- (C) 303°K
- (D) 0°K
14. The ratio of the useful heat drop to the isentropic heat drop is called
- (A) Condenser
efficiency
- (B) Nozzle
efficiency
- (C) Boiler
efficiency
- (D) Vacuum
efficiency
15. The fire tubes in a Scotch marine boiler are
- (A) Horizontal
- (B) Vertical
- (C) Inclined
- (D) None
of these