Electric Circuits Questions and Answers – Inductor and Capacitor

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

1. The symbol used for inductance is __________
a)
The symbol used for inductance - option a

b)
The symbol used for inductance - option b

c)
The symbol used for inductance - option c
d)
The symbol used for inductance - option d
View Answer

Answer: c
Explanation: The symbol used for inductance - option c is the symbol used to represent inductance.

2. The symbol used for capacitance is _____________
a)
The symbol used for inductance - option d
b)
The symbol used for inductance - option b
c)
The symbol used for inductance - option c
d)
The symbol used for inductance - option b
View Answer

Answer: b
Explanation: The symbol used for inductance - option b is the symbol used to represent capacitance.
advertisement

3. The formula used to find the capacitance C is __________
a) Q/v
b) Qv
c) Q-v
d) Q + v
View Answer

Answer: a
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

Answer: a
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.
Free 30-Day C++ Certification Bootcamp is Live. Join Now!

5. The Inductor doesn’t allow sudden changes in ___________
a) Voltage
b) Current
c) Resistance
d) Inductance
View Answer

Answer: b
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 L2I
d) ½ LI2
View Answer

Answer: d
Explanation: E=∫p dt
=∫ LI*(dI/dt).dt
= L∫I dI
= ½ LI2.

7. The units for inductance is _________ and capacitance is ___________
a) Faraday, Henry
b) Coulomb, Faraday
c) Henry, Faraday
d) Henry, Coulomb
View Answer

Answer: c
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.
The current for 0-1msec is 5A if voltage applied to a pure capacitor of 50*10-6 F
a) 5A
b) 1A
c) -5A
d) -1A
View Answer

Answer: a
Explanation: For 0≤t≤1msec,
V (t) =m*t (y=mx form)
→100= 1*10-3*m →m= 1*105
→ V (t) = 1*105t
Current I (t) = c. d (v (t))/dt = 50*10-6* (d (1*105t)/dt) = 5A.
advertisement

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

Answer: b
Explanation: E= ½ cv2.

10. The voltage applied to the 212mH inductor is given by v(t)= 15e-5tv. Calculate the current.
a) 16.782e-10t
b) 15.75e-5t
c) 11.27e-10t
d) 14.15e-5t
View Answer

Answer: d
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

Answer: a
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

Answer: b
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

Answer: b
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
View Answer

Answer: d
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 5.3t2+4.7t. Calculate the power.
a) 0
b) 1
c) 16.854t3+22.41t2+6.62t
d) 15.3t3+27.8t2+19
View Answer

Answer: c
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.

advertisement
advertisement
Subscribe to our Newsletters (Subject-wise). Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

Youtube | Telegram | LinkedIn | Instagram | Facebook | Twitter | Pinterest
Manish Bhojasia - Founder & CTO at Sanfoundry
I’m Manish - Founder and CTO at Sanfoundry. I’ve been working in tech for over 25 years, with deep focus on Linux kernel, SAN technologies, Advanced C, Full Stack and Scalable website designs.

You can connect with me on LinkedIn, watch my Youtube Masterclasses, or join my Telegram tech discussions.

If you’re in your 40s–60s and exploring new directions in your career, I also offer mentoring. Learn more here.