1) Compared to transistor,__________ have lower on state conduction losses and high power handling capability
a)
Triacs
b)
semi conductor diodes
c)
MOSFETs
d)
Thyristors
2). BTC is used for
a)
High power phase control
b)
High power current control
c)
Low power current control
d)
Low power phase control
3). A thyristor can termed as
a)
DC Switch
b)
AC Switch
c)
Both A abd B
d)
Square wave Switch
4). Which of the following device has highest
di/dt and dv/dt capability
a)
SIT
b)
SITH
c)
GTO
d)
SCR
5).Which of the following is disadvantage of fast recovery diodes?
a)
Doping is carried out
b)
Recovery is only 5μs
c)
Recovery is only 50μ
d)
Non of these
6). If the anode current is 800 A,then the amount of current required to turn off the GTO is about
a)
20 A
b)
600 A
c)
400 A
d)
200 A
7).The latching current of GTO should be of order ?
a)
100 mA
b)
500 mA
c)
1 A
d)
2 A
8).The GTO can be turned off
a)
By a positive gate pulse
b)
By a negative gate pulse
c)
By a negative anode- cathode voltage
d)
By removing gate pulse
9).Switching frequency of SITH is
a)
5 KHz
b)
10 KHz
c)
60 KHz
d)
100 KHz
10). The function of snubber circuit connected across the SCR is to
a)
Suppress dv/dt
b)
Increase dv/dt
c)
Decrease dv/dt
d)
Decrease di/dt
