Materials used in heat sink should have:
A. high thermal conductivity
B. large surface area
C. high melting point
D. All of these
A thyristor can termed as:
A. AC switch
B. DC switch
C. Both a and B
D. Square wave switch
Which of the following is used in heat sink:
A. Iron
B. Aluminium
C. Carbon
D Silver
How can we protect SCR from thermal conditions:
A. Use of snubber circuit.
B. Using heat sink.
C. Using CB and fuse.
D. Using equalizing circuit
Thyristor is nothing but a:
A. Controlled transistor
B. Controlled switch
C. Amplifier with higher gain
D. Amplifier with large current gain
Gate circuit or triggering circuit of a thyristor is:
A. lower power circuit.
B. high power circuit.
C. magnetic circuit.
D. may be low power or high power circuit
After proper turn on of thyristor:
A. gate signal is always present
B. gate signal must be removed
C. gate signal should present
D. none of the above.
What is used to protect a thyristor from high di / dt conditions:
A. Fuse.
B. Snubber circuit
C. Inductor
D. Voltage clamping device
COOLMOS device can be used in application up to power range of:
A. 1 KVA
B. 2 KVA
C. 500 VA
D. 100 KVA
Snubber circuit is used with SCR:
A. in series
B. in parallel
C. either series or parallel
D. anti parallel
Why resistor is used in Snubber circuit:
A. To minimize the loss
B. To minimize the charging current
C. To minimize the discharging current
D. All of these
What may happen high dV / dt:
A. Unwanted turn ON
B. Breakdown of J2 junction
C. Both A and B
D. Anyone of these
Thermal voltage VT can be given by:
A. Kq/T
B. KT/q
C. qT/K
D. (K2/q)(T + 1/T – 1)
IGBT combines the advantages of:
A. BJTs and SITs
B. BJTs and MOSFETs
C. SITs and MOSFETs
D. None of these
Which of the following is used in SCR to protect from high dV / dt:
A. Snubber circuit
B. Fuse
C. Equalizing circuit
D. Circuit breaker
