CS/B.Tech/PWE (OLD)/SEM-6/PWE-603/2013
2013
ELECTRICAL EQUIPMENT IN POWER STATION
Time Allotted : 3 Hours Full Marks : 70
The figures in the margin indicate full marks.
Candidates are required to give their answers in their own words
as far as practicable.
GROUP – A
( Multiple Choice Type Questions )
1. Choose the correct alternatives for the following :
10 × 1 = 10
i) The advantage of star connected supply system is that
a) Line current is equal to phase current.
b) Two level voltage can be used
c) Phase sequence can easily be done
d) It is a simple arrangement.
ii) The rotor of a turbo-alternator is made cylindrical in
order to reduce
a) Eddy current loss b) hysteresis loss
c) Windage loss d) Stray copper loss.
iii) In static excitation system at the time of initial voltage
build up the supply from
a) Generator terminal itself
b) Auxiliary supply source
c) Pilot excitor
d) AVR.
iv) Retaining ring or endring ring are used
a) For feeding DC to field winding of rotor
b) To prevent gas leakage from generator
c) To hold rotor over hang winding in position
d) To dampen double frequency effect.
v) Seal oil supply to sealing rings is provided by
a) Expansion tank b) Main oil tank
c) Hydraulic tank d) Damper tank.