Explore topic-wise MCQs in Electrical Engineering.

This section includes 216 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.

101.

The flow of electrons in dielectric is due to _________

A. Conduction
B. Potential difference
C. Breakdown
D. Resistance
Answer» D. Resistance
102.

If a parallel plate capacitor of plate area 2m² and plate separation 1m store the charge of 1.77*10¯¹¹ C. What is the voltage across the capacitor?

A. 1V
B. 2V
C. 3V
D. 4V
Answer» B. 2V
103.

If the charge in a capacitor is 4C and the energy stored in it is 4J, find the value of capacitance.

A. 2F
B. 4F
C. 8F
D. 16F
Answer» B. 4F
104.

Which of the following expressions is correct with respect to the voltage across capacitors in series?

A. V1/V2=C2/C1
B. V2/V1=C2/C1
C. V1*V2=C1*C2
D. V1/C1=V2/C2
Answer» B. V2/V1=C2/C1
105.

For very low frequencies, capacitor acts as ________

A. Open circuit
B. Short circuit
C. Amplifier
D. Rectifier
Answer» B. Short circuit
106.

A capacitor consists of_________

A. Two conductors
B. Two semiconductors
C. Two dielectrics
D. Two insulators
Answer» B. Two semiconductors
107.

For high frequencies, capacitor acts as _________

A. Open circuit
B. Short circuit
C. Amplifier
D. Rectifier
Answer» C. Amplifier
108.

What is the voltage across a capacitor at the time of switching, that is, when t=0?

A. Infinity
B. 0V
C. Cannot be determined
D. 1V
Answer» C. Cannot be determined
109.

If a 2F capacitor has 1C charge, calculate the voltage across its terminals.

A. 0.5V
B. 2V
C. 1.5V
D. 1V
Answer» B. 2V
110.

Which among the following expressions relate charge, voltage and capacitance of a capacitor?

A. Q=C/V
B. Q=V/C
C. Q=CV
D. C=Q²V
Answer» D. C=Q²V
111.

Calculate the time constant of a series RC circuit consisting of a 100microF capacitor in series with a 100ohm resistor.

A. 0.1 sec
B. 0.1 msec
C. 0.01 sec
D. 0.01 msec
Answer» D. 0.01 msec
112.

Capacitors charge and discharge in __________ manner.

A. Linear
B. Constant
C. Square
D. Exponential
Answer» E.
113.

A power factor of a circuit can be improved by placing which, among the following, in a circuit?

A. Inductor
B. Capacitor
C. Resistor
D. Switch
Answer» C. Resistor
114.

When the supply frequency increases, what happens to the capacitive reactance in the circuit?

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero
Answer» C. Remains the same
115.

N capacitors having capacitance C are connected in series, calculate the equivalent capacitance.

A. C/N
B. C
C. CN
D. N/C
Answer» E.
116.

Electric field terminates at ________

A. Positive charge
B. Negative charge
C. Neither positive nor negative
D. Both positive and negative
Answer» C. Neither positive nor negative
117.

When the potential gradient increases, what happens to the force between the plates?

A. Increases
B. Decreases
C. Remains the same
D. becomes zero
Answer» B. Decreases
118.

Find the number of plates in the multi plate capacitor having C=20F absolute permittivity=5F/m, A=4m² and d=2m.

A. 1
B. 2
C. 3
D. 4
Answer» D. 4
119.

Energy stored in 2000mF capacitor charged to a potential difference of 10V is?

A. 100J
B. 200J
C. 300J
D. 400J
Answer» B. 200J
120.

If the potential difference in a material is 4MV and the thickness of the material is 2m, calculate the dielectric strength.

A. 2MV/m
B. 4MV/m
C. 6MV/m
D. 8MV/m
Answer» B. 4MV/m
121.

Under normal conditions capacitors have _______

A. Displacement current
B. Conduction current
C. Both conduction and displacement current
D. Neither conduction nor displacement current
Answer» B. Conduction current
122.

If the dielectric strength of a material is 4MV/m and its potential difference is 28MV, calculate the thickness of the material.

A. 4m
B. 7m
C. 5m
D. 11m
Answer» C. 5m
123.

A capacitor using chemical reactions to store charge is _______

A. Paper capacitor
B. Ceramic capacitor
C. Polyester capacitor
D. Electrolyte capacitor
Answer» E.
124.

The flow of electrons which does not pass through the battery is known as ____________

A. Conduction current
B. Leakage current
C. Charging current
D. Displacement current
Answer» B. Leakage current
125.

The current in conductors connecting the voltage source to the plates of a capacitor is ______

A. Conduction current
B. Leakage current
C. Charging current
D. Zero
Answer» D. Zero
126.

The electric field strength is 10N/C and the thickness of the dielectric is 3m. Calculate the potential drop in the dielectric.

A. 10V
B. 20V
C. 30V
D. 40V
Answer» D. 40V
127.

A circuit has a resistance of 2 ohms connected in series with a capacitance of 6F. Calculate the discharging time constant.

A. 3
B. 1
C. 12
D. 8
Answer» D. 8
128.

A capacitor is charged to a voltage of 400V and has a resistance of 20ohm. Calculate the initial value of charging current.

A. 10A
B. 0A
C. Infinity
D. 20A
Answer» E.
129.

If one plate of a parallel plate capacitor is charged to positive charge the other plate is charged to?

A. Positive
B. Negative
C. Positive or negative
D. Not charged
Answer» C. Positive or negative
130.

When the voltage across a capacitor increases, what happens to the charge stored in it?

A. Increases
B. Decreases
C. Becomes zero
D. Cannot be determined
Answer» B. Decreases
131.

A circuit has a resistance of 5 ohm connected in series with a capacitance of 10F. Calculate the discharging time constant.

A. 15
B. 50
C. 5
D. 10
Answer» C. 5
132.

When will capacitor fully charged?

A. When the voltage across its plates is half the voltage from ground to one of its plates
B. When the current through the capacitor is a 1/√2 time its value
C. When the supply voltage is equal to the capacitor voltage
D. Never
Answer» D. Never
133.

What happens to the current flow in a fully charged capacitor?

A. Current flow stops
B. Current flow doubles
C. Current flow becomes half its original value
D. Current flow becomes one-fourth its original value
Answer» B. Current flow doubles
134.

What is the relation between current and voltage in a capacitor?

A. I=1/C*integral(Vdt)
B. I=CdV/dt
C. I=1/CdV/dt
D. I=Ct
Answer» C. I=1/CdV/dt
135.

Calculate the current in the capacitor having 2V supply voltage and 3F capacitance in 2seconds.

A. 2A
B. 5A
C. 6A
D. 3A
Answer» E.
136.

Calculate the energy in the 4F capacitor.

A. 128kJ
B. 1.28kJ
C. 12.8kJ
D. 1280J
Answer» D. 1280J
137.

Calculate the voltage across the capacitor at t=0.

A. 0V
B. 10V
C. 20V
D. Infinity
Answer» B. 10V
138.

Calculate the energy stored in the combination of the capacitors.

A. 192kJ
B. 1.92kJ
C. 19.2kJ
D. 1920J
Answer» D. 1920J
139.

What is the voltage across the 2F capacitor?

A. 240V
B. 200V
C. 220V
D. 120V
Answer» E.
140.

Calculate the voltage across the 6F capacitor.

A. 120V
B. 60V
C. 40V
D. 220V
Answer» D. 220V
141.

If the switch is closed at t=0, what is the current in the circuit?

A. 0A
B. 10A
C. 20A
D. Infinity
Answer» C. 20A
142.

What is the voltage across the 4F capacitor?

A. 120V
B. 60V
C. 100V
D. 220V
Answer» C. 100V
143.

Calculate the total charge of the system.

A. 200C
B. 100C
C. 300C
D. 400C
Answer» D. 400C
144.

What is the equivalent capacitance?

A. 1.5F
B. 0.667F
C. 2.45F
D. 2.75F
Answer» C. 2.45F
145.

Calculate the charge in the circuit.

A. 66.67C
B. 20.34C
C. 25.45C
D. 30.45C
Answer» B. 20.34C
146.

Calculate the voltage across the 1F capacitor.

A. 33.33V
B. 66.67V
C. 56.56V
D. 23.43V
Answer» C. 56.56V
147.

Calculate the voltage across the 2F capacitor.

A. 33.33V
B. 66.67V
C. 56.56V
D. 23.43V
Answer» B. 66.67V
148.

The current equation for the given circuit is?

A. a
B. b
C. c
D. d
Answer» B. b
149.

Calculate di(0)/dt if the switch is closed at t=0.

A. -9.9A/s
B. -10A/s
C. 0A/s
D. -0.1A/s
Answer» E.
150.

Calculate d²i(0)/dt² from the given circuit.

A. 10⁻⁶A/s²
B. 10⁻³A/s²
C. 10⁶A/s²
D. 10³A/s²
Answer» C. 10⁶A/s²