Explore topic-wise MCQs in Analog Electronic Circuits.

This section includes 12 Mcqs, each offering curated multiple-choice questions to sharpen your Analog Electronic Circuits knowledge and support exam preparation. Choose a topic below to get started.

1.

A single phase half wave rectifier is feeding a resistive load. When a = 0, dc output voltage is 127 V. When a = 30°, the dc output voltage will be about

A. 127 V
B. 120 V
C. 110 V
D. 100 V
Answer» C. 110 V
Discussion
2.

Figure shows a chopper feeding RLE load, The free wheeling diode conducts when

A. thyristor is on
B. thyristor is off
C. both when thyristor is on and thyristor is off
D. partly when thyristor is off and partly when thyristor is on
Answer» C. both when thyristor is on and thyristor is off
Discussion
3.

If V dc 1 is the dc output voltage in half wave controlled rectifier circuit feeding resistive load and V dc 2 is the dc output voltage in full wave controlled rectifier circuit (M - 2 connection) feeding resistive load, then

A. V dc 1 = 0.5 V dc 2 for all values of firing angle
B. V dc 1 = V dc 2 for all values of firing angle
C. V dc 1 ? 0.5 V dc 2 for all values of firing angle
D. V dc 1 ? 0.5 V dc 2 for all values of firing angle
Answer» B. V dc 1 = V dc 2 for all values of firing angle
Discussion
4.

A single phase half wave controlled rectifier circuit has a free wheeling diode. The load is a combination of R and L. The firing angle is a . The period of conduction of SCR and free wheeling diode respectively are

A. a < ? t < p and p < ? t < (2 p + a )
B. a < ? t < p and p < ? t < 2 p
C. a < ? t < ( p + a ) and ( p + a ) < ? t < 2 p
D. a < ? t < p and p < ? t < (2 p - a )
Answer» B. a < ? t < p and p < ? t < 2 p
Discussion
5.

A dc separately excited motor has constant field current. The armature is fed from a single phase supply through a full converter. When a = 0, speed is 500 rpm. If a = 45°, the speed is likely to be

A. about 350 rpm
B. about 250 rpm
C. about 175 rpm
D. about 125 rpm
Answer» E.
Discussion
6.

The dynamic equalising circuit consists of a series combination of capacitor C and resistor R C across each thyristor. This resistance R C (along with parallel connected diode)

A. limits charging current
B. limits discharging current
C. limits both charging and discharging currents
D. none of the above
Answer» C. limits both charging and discharging currents
Discussion
7.

A two winding transformer is feeding a single phase half wave rectifier circuit. The load is purely resistive. The rms value of transformer secondary current is I s and rms value of load current in I rms . Then

A. I s = I rms irrespective of the value of firing angle
B. I s = 0.5 I rms irrespective of the value of firing angle
C. I s = I rms if firing angle is less than 30°
D. I s = I rms if firing angle is more than 30°
Answer» B. I s = 0.5 I rms irrespective of the value of firing angle
Discussion
8.

In a step down chopper using pulse width modulation, T on = 3 x 10 -3 and T off = 1 x 10 -3 s. The chopping frequency is

A. 333.33
B. 250
C. 500
D. 1000
Answer» C. 500
Discussion
9.

The characteristics of a non-linear resistance is i = kv 4 . If i becomes 100 times, v becomes

A. about 100 times
B. about 10 times
C. about 3 times
D. about twice
Answer» D. about twice
Discussion
10.

An SCR is triggered at 40° in the positive half cycle only. The average anode current is 50 A. If the firing angle is changed to 80°, the average anode current is likely to be

A. 50 A
B. 25 A
C. less than 50 A but more than 25 A
D. less than 25 A
Answer» D. less than 25 A
Discussion
11.

In the below figure the average load current is 15 A. The rms value of transformer secondary current is

A. 15 A
B. 10.61 A
C. 7.5 A
D. 14.14 A
Answer» C. 7.5 A
Discussion
12.

A thyristor has a maximum allowable junction temperature of 120°C and the ambient temperature is 40°C. If thermal resistance is 1.6° C/W, the maximum allowable internal power dissipation is

A. 20 W
B. 50 W
C. 92 W
D. 128 W
Answer» C. 92 W
Discussion