Wayground logo

Free Printable Worksheets

Font size

S
M
L
XL
Worksheets

Power Electronics - 2

Total questions: 10

Worksheet time: 6mins

Name
Class
Date
1.

A single-phase full-bridge diode rectifier feeds a resistive load of 50 Ω from a 200V,

50Hz single-phase AC supply. If the diodes are ideal, then the active power drawn by the

load is ………... (round of nearest integer)

a)

200

b)

1600

c)

500

d)

800

2.

RC-IGCTs are known as

a)

Symmetrical IGTCs can be fabricated with reverse conducting

diode in the same package.

b)

Symmetrical IGCTs can be fabricated with reverse conducting SCR in the same

package.

c)

Asymmetrical IGCTs can be fabricated with high leakage inductance in the same

package.

d)

Asymmetrical IGCTs can be fabricated with reverse conducting diode in the

same package

3.

dv/dt protection is provided to the SCR by

a)

dv/dt protection is provided to the SCR by

b)

connecting an inductor in series with the load

c)

connecting a capacitor & resister in parallel with the device

d)

connecting an inductor & resister in parallel with the device

4.

An SCR has a half-cycle surge current rating of 3000 A for 50 Hz. Calculate its

one-cycle surge current rating

a)

3121.32 A

b)

2121.32 A

c)

3131.32 A

d)

2131.32 A

5.

Choose the correct statement

a)

MOSFET has a positive temperature co-efficient

b)

MOSFET has a high gate circuit impedance

c)

MOSFET is a voltage controlled device

d)

All of the mentioned

6.

A single-pulse transformer with secondary voltage of 230 V, 50 Hz, delivers power

to bulb of R = 10 Ω through a half-wave- controlled rectifier circuit. For α = 60°

and output AC power of 2127 Watts, find the rectification efficiency

a)

98.6 %

b)

42 %

c)

28 %

d)

19 %

7.

A single-phase full converter bridge is connected to the RLE load. The source

voltage is 230 V, 50 Hz. The average load current of 10 A is continuous over the

working range. For R=0.4 ohm and L = 2mH, find the firing angle delay (in

degree) for E=120 V

a)

32.12°

b)

43.51°

c)

53.21°

d)

71.21°

8.

A single phase fully controlled bridge rectifier is operated from 240 V, 50 Hz ac mains

with firing angle 30°. Load draws a continuous and ripple free current of 12 A. Then

which of the following is correct

a)

Average output voltage is 187.12 V

b)

Rms value of source current is 6 A

c)

Reactive power drawn from the supply is 1296 kVAR

d)

Real power drawn from the supply is 3245.4 W

9.

A 230 V, 50 Hz, one-pulse SCR controlled converter has extinction angle β = 200°.

Find the circuit turn-off time

a)

10 m-sec

b)

0

c)

8.9 m-sec

d)

5.4 m-sec

10.

Which of the following is a common technique to enhance the performance of gate

drivers?

a)

Using low power supply voltage

b)

Increasing the gate resistance

c)

Adding a bootstrap circuit for high-side drive

d)

Using a single-ended configuration