MCQ

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POWER ELECTRONICS & DRIVES

Q1. The reverse recovery time of diode \(t_{rr} = 3.5 \:\mu s\) and the stored charge \(Q_{RR} = 122.5\:\mu C \). Calculate the rate of change of the diode current \(di/dt \).

Q2. The average output voltage \(V_{dc}\) of a half-wave rectifier with resistive load can be given by following expression, where \(V_m\) is the maximum or peak voltage of the AC sinusoidal supply.

Q3. A single-phase full-wave uncontrolled bridge rectifier is supplying a highly inductive load (L/R ratio is very large), the load current is assumed to be smooth and ripple –free. If the supply voltage is 230V, 50Hz, and the inductor load resistance R = 20 \(\Omega\), Calculate the average output current.

Q4. An ideal 230 V, 50 Hz single-phase AC source supplies power to a load resistor \(100\:\Omega\) through a single ideal diode. Calculate the average value of the current.

Q5. In a 3 phase fully controlled converter the firing frequency is

Q6. In a thyristor, the holding current is

Q7. AC voltage regulators are widely used in

Q8. Why resistor is used in snubber circuit?

Q9. In SMPS, during ON mode, the switch is in _________ mode.

Q10. In reverse blocking mode of a thyristor