Explore topic-wise MCQs in Electronics.

This section includes 177 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.

151.

What is the impedance of a series RC circuit that consists of a 0.22 F capacitor and a 200-ohm resistor connected to a 3 kHz source?

A. 214 ohms
B. 313 ohms
C. 414 ohms
D. 880 ohms
Answer» C. 414 ohms
152.

Which material has the highest dielectric strength?

A. Air
B. Paper
C. Mica
D. Oil
Answer» D. Oil
153.

What is the dielectric constant for ceramic?

A. between 6 and 8000
B. 5
C. between 5 and 1000
D. 3000
Answer» B. 5
154.

A ___ capacitor allows ac signals to pass while blocking dc signals.

A. filter
B. bypass
C. decoupling
D. coupling
Answer» E.
155.

If the reactive power of a circuit is 50 mW while the apparent power is 64 mW, then what is the true power of the circuit?

A. 14 mW
B. 36 mW
C. 40 mW
D. 114 mW
Answer» D. 114 mW
156.

How is ac current related to ac voltage in a purely capacitive circuit?

A. AC current is 0.707 of the ac voltage.
B. AC current lags ac voltage.
C. AC current is 0.637 of the ac voltage.
D. AC current leads ac voltage.
Answer» E.
157.

The strength of an electric field at a given point is proportional to the potential difference on the plates and inversely proportional to the:

A. plate separation
B. negative plate only
C. field strength
D. charge difference
Answer» B. negative plate only
158.

When a 4.7 F capacitor is connected to a 1 kHz source, what is its capacitive reactance?

A. 4.7 ohms
B. 29.5 ohms
C. 34 ohms
D. 213 ohms
Answer» D. 213 ohms
159.

In a capacitive circuit, current flow is limited to

A. charging periods
B. discharging periods
C. neither charging periods nor discharging periods
D. both charging periods and discharging periods
Answer» E.
160.

What is the reactive power in the given circuit?

A. 0 VAR
B. 691 VAR
C. 44.23 mVAR
D. 1.45 kVAR
Answer» D. 1.45 kVAR
161.

Which of the following is the reference vector for parallel RC circuits?

A. R
B. I
C. C
D. V
Answer» E.
162.

If a current of 40 mA flows through a series circuit consisting of a 0.4 F capacitor and a resistor in series with a 4 kHz, 40 Vac source, what is the total circuit impedance?

A. 10
B. 100
C. 1 k
D. 1 M
Answer» D. 1 M
163.

What is the voltage across a capacitor after being charged from a 100 V source for a period of one time constant?

A. 37.8 V
B. 38 V
C. 63 V
D. 101 V
Answer» D. 101 V
164.

If a 5 V, 60 Hz voltage is applied to a 4.7 F capacitor, the circuit current will be ______ .

A. 0.886 mA
B. 8.86 mA
C. 8.86 A
D. 88.6 A
Answer» C. 8.86 A
165.

What is the angle theta value for a 5.6 F capacitor and a 50-ohm resistor in series with a 1.1 kHz, 5 Vac source?

A. 27.3 degrees
B. 62.7 degrees
C. –27.3 degrees
D. –62.7 degrees
Answer» D. ‚Äì62.7 degrees
166.

What is the circuit's impedance?

A. 1192
B. 843
C. 723
D. 511
Answer» B. 843
167.

Select the equation below that represents the relationship between charge, capacitance, and voltage for a capacitor.

A. Q = CV
B. C = QV
C.
Answer» B. C = QV
168.

What will a 1 F capacitor store?

A. one coulomb of charge
B. 6.24 x 1012 electrons
C. one volt
D. one A of current
Answer» C. one volt
169.

What is the phase shift between the voltage across the resistor and the voltage from the source?

A. VR leads VS by 17°
B. VR leads VS by 73°
C. VR lags VS by 73°
D. VR lags VS by 17°
Answer» C. VR lags VS by 73¬∞
170.

What is the capacitive reactance if I = 1 amp, V = 2 volts, C = 5 F, and frequency = 10 Hz?

A. 0.2
B. 0.5
C. 0.02
D. 0.003
Answer» E.
171.

How long would it take the capacitor in the given circuit to completely charge if the switch was in position 1?

A. 22 ms
B. 69 ms
C. 345 ms
D. 440 ms
Answer» D. 440 ms
172.

A capacitor and an output resistor form a series circuit with a square wave applied. The circuit is:

A. an integrator
B. a differentiator
C. a multiplier
D. a divider
Answer» C. a multiplier
173.

A capacitor's rate of charge is considered:

A. magnetic
B. a current block
C. linear
D. exponential
Answer» E.
174.

When is a capacitor fully charged?

A. when the voltage across its plates is of the voltage from ground to one of its plates
B. when the current through the capacitor is the same as when the capacitor is discharged
C. when the voltage across the plates is 0.707 of the input voltage
D. when the current through the capacitor is directly proportional to the area of the plates
Answer» C. when the voltage across the plates is 0.707 of the input voltage
175.

Capacitive reactance is inversely proportional with frequency.

A. 1
B.
C. 1
D.
Answer» B.
176.

If C1, a 4.7 F capacitor, and C2, a 3.3 F capacitor are in series with 18 Vdc applied, what is the voltage across C1?

A. 3.3 V
B. 7.4 V
C. 6.6 V
D. 9.4 V
Answer» C. 6.6 V
177.

In a 20 Vac series RC circuit, if 20 V is measured across the resistor and 40 V is measured across the capacitor, the applied voltage is:

A. 45 V
B. 50 V
C. 55 V
D. 60 V
Answer» B. 50 V