This set of Electric Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Inductor and Capacitor”.
3. The formula used to find the capacitance C is __________
d) Q + v
Explanation: Q=cv. Q-charge, V-voltage, c-capacitance.
4. The capacitor doesn’t allow sudden changes in ___________
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 ___________
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
c) ½ L2I
d) ½ LI2
Explanation: E=∫p 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
Explanation: The unit for inductance is ‘Henry’ and capacitance is ‘Faraday’.
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.
9. If a capacitor of capacitance 9.2F has a voltage of 22.5V across it. Calculate the energy of the capacitor.
Explanation: E= ½ cv2.
10. The voltage applied to the 212mH inductor is given by v(t)= 15e-5tv. Calculate the current.
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
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
Explanation: i= C*(dv/dt).
12. If the voltage across a capacitor is constant, then current passing through it is ________
Explanation: I= c*(dv/dt).
13. An Inductor works as a ___________ circuit for DC supply.
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 __________
b) Capacitive medium
c) Conducting medium
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.
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.