Power Systems - I Mid - I, February - 2012

1.In a thermal power plant, heat from the flue gases is recovered in
  • chimney
  • de-super heater
  • economizer
  • condenser
Answer: C
2.Which of the following enters the super heater of a boiler ?
  • Cold water
  • Hot water
  • Wet steam
  • Super-heated steam.
Answer: C
3.Overall thermal efficiency of a steam power station is in the range
  • 18-24%
  • 30-40%
  • 44-62%
  • 68-79%
Answer: A
4.Which of the following material can be used as a moderator ?
  • Graphite
  • Heavy water
  • Beryllium
  • Any of the above
Answer: D
5.A fast breeder reactor
  • operates with fast neutrons and produces less fissionable material than it consumes
  • operates with fast neutrons and produces more fissionable material than it consumes
  • operates with slow neutrons and produces less fissionable material than it consumes
  • operates with slow neutrons and produces more fissonable material than it consumes
Answer: B
6.Which distribution system is more reliable ?
  • Ring main system
  • Tree system
  • Radial system
  • All are equally reliable
Answer: A
7.For purely domestic loads,________ a.c. system is employed for distribution
  • single phase 2-wire
  • 3-phase 3-wire
  • 3-phase 4-wire
  • none of these
Answer: A
8.3-phase, 4-wire a.c. system of distribution is used for
  • balanced load
  • unbalanced load
  • domestic load
  • both (A) & (B)
Answer: B
9.In a 3-wire system, the area of X-section of neutral is generally ______of either outer
  • same
  • half
  • double
  • thrice
Answer: B
10.A regenerator in a gas turbine
  • reduces heat loss in exhaust
  • permits use of higher compression ratio
  • improves thermal efficiency
  • permits use of fuels of inferior quality
Answer: C
11.In steam power plants exhaust steam from turbine goes to __________.
Answer: condenser
12.A thermal power station basically works on __________ cycle.
Answer: Rankine
13.The two types of steam turbines are __________ and _____________.
Answer: Impulse & Reaction turbines
14._________ is used as both moderator and coolant in boiling water reactor (BWR).
Answer: water
15.The reactions taking place in a nuclear reactor is ____________.
Answer: Nuclear fission or chain reactions
16.In a 3 wire d.c. system , the load on ve side is 400A and on negative side it is 300A .
Then current in neutral wire is _______.
Answer: 100A
17.A distributor is designed from _____________ considerations.
Answer: voltage drop
18.The most common system for secondary distribution is 400/_____V, 3-phase , ____ wire system.
Answer: 230V, 4-wire
19.In a 3-phase, 4-wire a.c. system, if the loads are balanced , then current in the neutral wire is _________.
Answer: zero
20.A booster is used to ___________ voltage drop in feeders etc.
Answer: compensate