This set of Electric Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Inductor and Capacitor”.

1. The symbol used for inductance is __________

a)

b)

2. The symbol used for capacitance is _____________

a)

b)

c)

d)

View Answer

3. The formula used to find the capacitance C is __________

a) Q/v

b) Qv

c) Q-v

d) Q + v

View Answer

Explanation: Q=cv. Q-charge, V-voltage, c-capacitance.

4. The capacitor doesn’t allow sudden changes in ___________

a) Voltage

b) Current

c) Resistance

d) Capacitance

View Answer

Explanation: Any small change in voltage occurs within zero time across the gives an infinite current which is practically impossible. So, in a fixed capacitor, the voltage cannot change abruptly.

5. The Inductor doesn’t allow sudden changes in ___________

a) Voltage

b) Current

c) Resistance

d) Inductance

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Explanation: Any small change in current occurs within zero time across the gives an infinite voltage which is practically impossible. So, in a fixed inductor, the voltage cannot change abruptly.

6. The expression for energy of an inductor ____________

a) ½ LI

b) L/2I

c) ½ L^{2}I

d) ½ LI^{2}

View Answer

Explanation: E=∫p dt

=∫ LI*(dI/dt).dt

= L∫I dI

= ½ LI

^{2}.

7. The units for inductance is _________ and capacitance is ___________

a) Faraday, Henry

b) Coulomb, Faraday

c) Henry, Faraday

d) Henry, Coulomb

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Explanation: The unit for inductance is ‘Henry’ and capacitance is ‘Faraday’.

8. The voltage applied to a pure capacitor of 50*10^{-6} F is as shown in figure. Calculate the current for 0-1msec.

a) 5A

b) 1A

c) -5A

d) -1A

View Answer

Explanation: For 0≤t≤1msec,

V (t) =m*t (y=mx form)

→100= 1*10

^{-3}*m →m= 1*10

^{5}

→ V (t) = 1*10

^{5}t

Current I (t) = c. d (v (t))/dt = 50*10

^{-6}* (d (1*10

^{5}t)/dt) = 5A.

9. If a capacitor of capacitance 9.2F has a voltage of 22.5V across it. Calculate the energy of the capacitor.

a) 5062.5W

b) 506.25W

c) 50.625W

d) 50625W

View Answer

Explanation: E= ½ cv

^{2}.

10. The voltage applied to the 212mH inductor is given by v(t)= 15e^{-5t}v. Calculate the current.

a) 16.782e^{-10t}

b) 15.75e^{-5t}

c) 11.27e^{-10t}

d) 14.15e^{-5t}

View Answer

Explanation: Current I(t)= 1/L 0∫t v*dt.

11. A voltage across a capacitor of 0.5F is defined by

V (t) = [0, t<0

2t, 0<t<2s

4e^{-(t-2)}, t>2s]
Find i (t).

a) -2e^{-(t-2)} A

b) -4e^{-(t-2)} A

c) -20e^{-(t-2)} A

d) -12e^{-(t-2)} A

View Answer

Explanation: i= C*(dv/dt).

12. If the voltage across a capacitor is constant, then current passing through it is ________

a) 1

b) 0

c) -1

d) Infinity

View Answer

Explanation: I= c*(dv/dt).

13. An Inductor works as a ___________ circuit for DC supply.

a) Open

b) Short

c) Polar

d) Non-polar

View Answer

Explanation: Induced voltage across an inductor is zero if the current flowing through it is constant. I.e. Inductor works as a short circuit for DC supply.

14. The insulating medium between the two plates of capacitor is known as __________

a) Electrode

b) Capacitive medium

c) Conducting medium

d) Dielectric

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Explanation: The conducting surfaces are called electrodes and the insulating medium is called Dielectric.

15. If the current flowing through an inductor of inductance 0.3Henry is 5.3t^{2}+4.7t. Calculate the power.

a) 0

b) 1

c) 16.854t^{3}+22.41t^{2}+6.62t

d) 15.3t^{3}+27.8t^{2}+19

View Answer

Explanation: P= L*i*(di/dt).

**Sanfoundry Global Education & Learning Series – Electric Circuits.**

To practice all areas of Electric Circuits, __here is complete set of 1000+ Multiple Choice Questions and Answers__.