Explore topic-wise MCQs in Electronic Devices.

This section includes 17 Mcqs, each offering curated multiple-choice questions to sharpen your Electronic Devices knowledge and support exam preparation. Choose a topic below to get started.

1.

The ripple voltage V is a result of the ________.

A. conduction of the diode(s)
B. transformer windings
C. charging and discharging of the capacitor
D. load resistor
Answer» D. load resistor
Discussion
2.

In Figure 17-1(a)(see question 6), the purpose of R is to

A. provide a reference voltage.
B. limit current through the diode.
C. limit voltage to the op-amp.
D. provide output voltage sampling.
Answer» C. limit voltage to the op-amp.
Discussion
3.

For a full-wave rectifier with ac ripple at 120 Hz, the impedance of a capacitor can be calculated using X = ________.

A. 0.707 ÷ C
B. 1.414 ÷ C
C. 1.3 ÷ C
D. 0.785 ÷ C
Answer» D. 0.785 ÷ C
Discussion
4.

Refer to the given figure. If the output of the circuit were to be a short circuit, what power rating would R need to have?

A. 2.25 W
B. 5 W
C. 10 W
D. 22.5 W
Answer» E.
Discussion
5.

Refer to the given figure. The purpose for the zener diode D is

A. to supply a reference voltage.
B. to amplify the error signal.
C. to sense the error signal.
D. to limit the input voltage to the circuit.
Answer» B. to amplify the error signal.
Discussion
6.

Calculate the dc voltage across a 2-k load for an RC filter section (R = 50 , C = 20 F). The dc voltage across the initial filter capacitor is V = 50 V.

A. 40.78 V
B. 42.78 V
C. 45.78 V
D. 48.78 V
Answer» E.
Discussion
7.

Refer to the given figure. If the load is short-circuited, what would be the maximum current through R?

A. 1 A
B. 1.2 A
C. 1.5 A
D. 5 A
Answer» D. 5 A
Discussion
8.

Refer to the given figure. If a solder splash shorted the ends of R to each other,

A. the op-amp would fail.
B. Q
C. would open.
D. the output voltage would not change.
E. the zener would fail.
Answer» E. the zener would fail.
Discussion
9.

Calculate the ripple of a capacitor filter for a peak rectified voltage of 40 V, a capacitor value C = 75 F, and a load current of 40 mA.

A. 3.2%
B. 3.59%
C. 4.03%
D. 4.59%
Answer» B. 3.59%
Discussion
10.

What are the typical values of Vand I for the LM317 adjustable voltage regulator?

A. 1.0 V, 100 mA
B. 1.5 V, 100 mA
C. 1.25 V, 100 μA
D. 1.25 V, 10 mA
Answer» D. 1.25 V, 10 mA
Discussion
11.

Calculate the ripple of a filter output having a 20-V dc component and a 1.7 V(rms) ac component.

A. 6%
B. 8.5%
C. 85%
D. 58%
Answer» C. 85%
Discussion
12.

Calculate the voltage regulation of a power supply having V = 50 V and V = 48 V.

A. 4.17%
B. 5.2%
C. 6.2%
D. 7.1%
Answer» B. 5.2%
Discussion
13.

If a peak rectified voltage for the full-wave filter circuit is 40 V, calculate the filter dc voltage if C = 75 F and load current is 40 mA.

A. 27.9 V
B. 32.12 V
C. 37.78 V
D. 40 V
Answer» D. 40 V
Discussion
14.

Refer to the given figure. If the BE junction of Q opens, the output voltage V will

A. increase.
B. decrease.
C. remain the same.
Answer» C. remain the same.
Discussion
15.

What regulated output voltage is provided for the following circuit elements: R = 15 k, R = 35 k, and V = 11.2 V?

A. 16.50 V
B. 17 V
C. 17.35 V
D. 18.25 V
Answer» C. 17.35 V
Discussion
16.

A voltage regulator with a no-load output dc voltage of 12 V is connected to a load with a resistance of 10 . If the load resistance decreases to 7.5 , the load voltage will decrease to 10.9 V. The load current will be ________, and the percent load regulation is ________.

A. 1.45 A, 90.8%
B. 1.45 A, 10.09%
C. 1.2 A, 90.8%
D. 1.2 A, 10.09%
Answer» C. 1.2 A, 90.8%
Discussion
17.

Calculate the ripple voltage of a full-wave rectifier with a 75-F filter capacitor connected to a load drawing 40 mA.

A. 1.20 V
B. 1.28 V
C. 1.32 V
D. 1.41 V
Answer» C. 1.32 V
Discussion