CS/B.Tech(PWE/NEW)/SEM-6/PWE-605B/2013
2013
POWER ELECTRONICS
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) A BJT can be turned on by
a) switching off the supply
b) applying an appropriate bias voltage
c) removing the bias voltage
d) none of these.
ii) A G.T.O. can be turned off from conduction state by
a) removing the gate pulse
b) connecting a reversely charged capacitor across
anode and cathode terminals
c) connecting an inductance between anode and
cathode terminals
d) applying an appropriate negative gate pulse at the
gate.
iii) A thyristor can be turned off by
a) connecting a reversely charged capacitor across its
anode and cathode terminals
b) gradually decreasing the load current below the
level of holding current
c) gradually decreasing the load current below the
level of latching current
d) can be switched by connecting a snubber circuit
across it terminals.