Explore topic-wise MCQs in Power Electronics.

This section includes 7 Mcqs, each offering curated multiple-choice questions to sharpen your Power Electronics knowledge and support exam preparation. Choose a topic below to get started.

1.

Find the value of the charging resistor in case of a UJT firing circuit with firing frequency of 2 kHz, C = 0.04 F, = 0.72

A. 5.62 k
B. 37 k
C. 4.23 k
D. 9.82 k
Answer» E.
2.

In the UJT firing circuit, the pulses are generated while the

A. capacitor charges
B. capacitor discharges
C. capacitor voltage is zero
D. there is no capacitor in a UJT firing circuit
Answer» C. capacitor voltage is zero
3.

In case of the UJT firing circuit, when the UJT turns on

A. the capacitor starts to charge
B. the capacitor starts to discharge
C. the capacitor remains unaffected
D. there is no capacitor in a UJT firing circuit
Answer» C. the capacitor remains unaffected
4.

The UJT terminals are

A. E, B1 and B2
B. E1, E2 and B
C. E, G and C
D. G, S and D
Answer» B. E1, E2 and B
5.

Pulse triggering can be only used by the _____________ type of triggering circuit

A. R
B. RC
C. UJT
D. RLC
Answer» D. RLC
6.

For an RC full wave firing circuit the empirical formula for calculating the value of RC is

A. RC = 157/
B. RC = 157 x
C. RC = /157
D. RC = 157 x <sup>2</sup>
Answer» B. RC = 157 x
7.

In case of an RC full wave firing circuit with R load, the voltage across the load is zero for____________

A. t = 0 to and t = to 2 +
B. t = 0 to
C. t = to 2 +
D. t = to 2
Answer» C. t = to 2 +