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.

101.

Power stored from the source and then returned to the source is called:

A. apparent power
B. impedance power
C. reactive power
D. true power
Answer» D. true power
102.

What is the dc charging/discharging time constant for the circuit?

A. 294 ps
B. 13.5 ms
C. 21.25 ms
D. 2.16 Gs
Answer» D. 2.16 Gs
103.

Which of the following determines the capacitance of a capacitor?

A. Plate area, dielectric strength, and plate separation
B. Voltage rating, dielectric constant, and temperature coefficient
C. Temperature coefficient, plate area, and plate separation
D. Plate area, dielectric constant, and plate separation
Answer» E.
104.

After which time constant can a capacitor be considered to be fully charged?

A. first
B. third
C. fifth
D. seventh
Answer» D. seventh
105.

What is the total current for a 5 MHz, 1 Vac circuit that consists of a 27 pF capacitor and a 1 k resistor connected in parallel?

A. 459 A
B. 647 A
C. 1.31 mA
D. 1.85 mA
Answer» D. 1.85 mA
106.

As a capacitor is being charged, current flowing into the capacitor will:

A. increase
B. decrease
C. remain the same
D. cannot tell
Answer» C. remain the same
107.

In an RC circuit, true power (PR) equals:

A.
B. VS √ó I
C. I2R
Answer» D.
108.

After a capacitor has charged for 1 tc, what percentage of current remains in the resistor?

A. 63.2
B. 36.8
C. 13.5
D. 5
Answer» C. 13.5
109.

A 10 F capacitor will have more capacitive reactance than a 20 F capacitor in a 60 Hz circuit.

A. 1
B.
Answer» B.
110.

You could increase the time constant of an RC circuit by

A. adding a resistor in parallel with the circuit resistance
B. adding a capacitor in parallel with the circuit capacitance
C. increasing the amplitude of the input voltage
D. exchanging the position of the resistor and capacitor in the circuit
Answer» C. increasing the amplitude of the input voltage
111.

In the given circuit, the voltage across the capacitor 1 ms after the switch is closed is 11.61 V.

A. 1
B.
C. 1
D.
Answer» C. 1
112.

The total capacitance in the given circuit is larger than the value of C4.

A. 1
B.
Answer» C.
113.

When a circuit consists of a capacitor and a resistor in series with a voltage source, and the voltage across the resistor is zero, then the capacitor is:

A. charging
B. discharging
C. fully charged
D. fully discharged
Answer» D. fully discharged
114.

The quantity that represents an ideal capacitor dissipating 0 W of power is

A. instantaneous power
B. true power
C. reactive power
D. resistive power
Answer» C. reactive power
115.

A resistor and an output capacitor 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» B. a differentiator
116.

What is the value of a capacitor that can store two coulombs of charge when 500 volts is applied across its plates?

A. 4 F
B. 250 F
C. 4,000 F
D. 250 F
Answer» D. 250 F
117.

What is the value of a capacitor labeled 102?

A. 10,000 pF
B. 1000 pF
C. 1000 F
D. 10,000 F
Answer» C. 1000 F
118.

What do variable capacitors use for dielectric?

A. ceramic, electrolytic, mica, or paper
B. air, ceramic, mica, or plastic
C. ceramic, paper, plastic, or mica
D. mica, ceramic, plastic, or electrolytic
Answer» C. ceramic, paper, plastic, or mica
119.

What is the circuit's total current?

A. 4.57 mA
B. 9.327 mA
C. 11.570 mA
D. 13.830 mA
Answer» B. 9.327 mA
120.

A capacitor has 25 V across its plates and a stored charge of 1500 C. What is the capacitance value?

A. 60 pF
B. 60 F
C. 16.67 mF
D. 37.5 mF
Answer» C. 16.67 mF
121.

An 8 V power source is charging a capacitor. How many volts will be across the capacitor at the second time constant?

A. 1 volt
B. 3 volts
C. 5 volts
D. 7 volts
Answer» E.
122.

Capacitor value markings are usually:

A. alphanumeric
B. color dabs
C. standard
D. white print
Answer» B. color dabs
123.

What is the impedance of an ac RC parallel circuit if the resistance is 12 ohms and the capacitive reactance equals 5 ohms?

A. 0.2 ohms
B. 3.5 ohms
C. 4.6 ohms
D. 13 ohms
Answer» D. 13 ohms
124.

A capacitor stores energy within a dielectric between the conducting plates in the form of:

A. a magnetic field
B. positive voltage
C. negative voltage
D. an electric field
Answer» E.
125.

What is the reactance value for a capacitor installed in a dc circuit?

A. zero
B. moderate
C. infinite
D. cannot tell
Answer» D. cannot tell
126.

A practical capacitor

A. is a short to dc
B. looks like a capacitor in parallel with a resistor
C. is an open to ac
D. stores energy in a magnetic field
Answer» C. is an open to ac
127.

What is the total opposition to current in a series RC circuit called?

A. impedance
B. inductance
C. reactance
D. resistance
Answer» B. inductance
128.

What is the capacitance of the circuit shown in the given circuit?

A. 0.066 F
B. 0.9 F
C. 65.97 pF
D. 900 pF
Answer» B. 0.9 F
129.

What is the impedance of this circuit?

A. 5928
B. 2000
C. 1902
D. 1798
Answer» B. 2000
130.

Ceramic capacitors have higher voltage ratings than electrolytic capacitors.

A. 1
B.
C. 1
D.
Answer» B.
131.

In a purely capacitive circuit,

A. current leads voltage by 90°
B. voltage leads current by 90°
C. current lags voltage by 90°
D. current and voltage have a phase relationship of 0°
Answer» B. voltage leads current by 90¬∞
132.

A capacitor can be fully charged in 4 time constants.

A. 1
B.
C. 1
D.
Answer» C. 1
133.

For a given charge difference, electrostatic field strength varies according to:

A. plate differential
B. plate area
C. plate distance
D. dielectric quantity
Answer» C. plate distance
134.

What is the total capacitance?

A. 1 F
B. 12 F
C. 0.615 F
D. 8 F
Answer» C. 0.615 F
135.

What is the reactive power?

A. 6.8 mW
B. 9.8 mW
C. 12.8 mW
D. 15.8 mW
Answer» C. 12.8 mW
136.

Most older types of paper capacitors have been replaced by which type of construction?

A. electrolytic
B. plastic film
C. oxide casing
D. waxed paper
Answer» C. oxide casing
137.

What is the power factor if the apparent power of a circuit is 5 W, while the true power is 4 W?

A. 0.0 W
B. 0.8 W
C. 1.0 W
D. 1.25 W
Answer» C. 1.0 W
138.

A capacitor is constructed of two parallel:

A. conductors
B. semiconductors
C. inductors
D. dielectrics
Answer» B. semiconductors
139.

What circuit has the following frequency response?

A. bandpass filter
B. high-pass filter
C. low-pass filter
D. integrator
Answer» D. integrator
140.

The material used between the plates of a capacitor is called its:

A. insulation material
B. dielectric material
C. separation material
D. plate-divider material
Answer» C. separation material
141.

If a capacitor is placed across a 20 V source, what will be the amount of charge after 5 tc?

A. 5.0 V
B. 12.8 V
C. 13.5 V
D. 20 V
Answer» E.
142.

What is wrong with a leaky capacitor?

A. It is open.
B. It is shorted.
C. The dielectric resistance has increased.
D. The dielectric resistance has decreased.
Answer» E.
143.

Capacitive reactance values connected in series offer

A. an increase in total XC
B. a decrease in total XC
C. no change in total XC
D. total opposition to voltage in the circuit
Answer» B. a decrease in total XC
144.

What is the voltage across the capacitor?

A. 7.07 V
B. 1.11 V
C. 111 mV
D. 7.07 mV
Answer» D. 7.07 mV
145.

___ capacitors have the highest values of capacitance.

A. Electrolytic
B. Ceramic
C. Plastic-film
D. Mica
Answer» B. Ceramic
146.

How long would it take the capacitor in the given circuit to completely discharge if the switch was in position 2?

A. 22 ms
B. 69 ms
C. 345 ms
D. 420 ms
Answer» E.
147.

A circuit whose output voltage is proportional to the rate of change of the input voltage is called a(n) ______ .

A. differentiator
B. integrator
C. curve averager
D. mixer
Answer» B. integrator
148.

A capacitor stores electric energy in the form of an electric field.

A. 1
B.
C. 1
D.
Answer» B.
149.

To find the total capacitance of capacitors in parallel, sum the values of the individual capacitors.

A. 1
B.
Answer» B.
150.

In an ac circuit, a capacitor and an output resistor are connected in series with an ac signal. What filter action will be the result?

A. bandpass
B. low-pass
C. high-pass
D. band-stop
Answer» D. band-stop