BCT is used for:
A. High power phase control
B. High power current control
C. Low power current control
D. Low power phase control
Which of following devices has highest di/dt and dv/dt capability:
A. SIT
B. SITH
C. GTO
D. SCR
Which triggering is the most reliable:
A. forward blocking mode
B. reverse blocking mode
C. both forward and reverse blocking mode
D. forward conduction mode
Which of the following is disadvantage of fast recovery diodes:
A. Recovery is only 5 µs
B. Recovery is only 50 µs
C. Doping is carried out
D. None of these
A power semiconductor may undergo damage due to:
A. High di/dt
B. High dv/dt
C. Low di/dt
D. Low dv/dt
If the anode current is 800 A, then the amount of current required to turn off the GTO is about:
A. 20 A
B. 200 A
C. 600 A
D. 400 A
What is used to protect the SCR from over current:
A. CB and fuse.
B. Heat sink.
C. Snubber circuit.
D. Voltage clamping device
Which semiconductor device acts like a diode and two transistor:
A. UJT
B. Diac
C. Triac
D. SCR
Under over voltage condition impedance offered by the voltage clamping device is:
A. low
B. High
C. moderate
D. infinity
The latching current of GTO should be of order:
A. 100 mA
B. 500 mA
C. 1 A
D. 2 A
The maximum di/dt in a SCR is:
A. Directly proportional to supply voltage
B. Directly proportional to inductance in the circuit
C. Inversely proportional to supply voltage
D. Both A and B
Example of a voltage clamping device:
A. fast acting fuse
B. snubber circuit
C. metal oxide varistor
D. aluminium block
Switching frequency of SITH is:
A. 5 KHz
B. 10 KHz
C. 60 KHz
D. 100 KHz
Thyristor can be protected from over voltages by using:
A. voltage clamping device.
B. fuse.
C. heat sink.
D. snubber circuit.
