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.Management Sciences
Category: Power Electronics
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.
Leakage current flows through the thyristor in_________?
A. forward blocking mode
B. reverse blocking mode
C. both forward and reverse blocking mode
D. forward conduction mode
In a 3 phase bridge rectifier the ripple frequency is _____________?
A. Equal to the input frequency
B. Twice the input frequency
C. Three times the input frequency
D. Six times the input frequency
The typical time of rising time lies between______________?
A. 10 – 20 µs
B. 40 – 60 µs
C. 1 – 4 µs
D. 90 – 100 µs
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 MOSFET has three terminals called___________?
A. Collector, emitter and gate
B. Drain, source and gate
C. Drain, source and base
D. Collector, emitter and base
The switching function of semiconductor devices can be characterized with___________?
A. Duty ratio only
B. Frequency only
C. Duty ratio and frequency
D. Duty ratio, frequency and time delay
The reverse recovery time of diode is trr = 3 μs and the rate off all of the diode current is di/dt = 30 A/μs. The storage charge current QRR is___________?
A. 130 μs
B. 135 μs
C. 140 μs
D. 145 μs
Which of the following is true about SIT?
A. SIT is a high power, high frequency device
B. SIT is a high power, low frequency device
C. SIT is a high power, high voltage device
D. SIT is a low power, high frequency device
A crowbar is a circuit which is used to protect a_____________?
A. voltage sensitive load from excessive dc power supply output voltages
B. current sensitive load from excessive dc power supply output voltages
C. voltage sensitive load from excessive ac power supply output voltages
D. current sensitive load from excessive ac power supply output voltages
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