Circuit Theory – Multiple Choice Questions (MCQs)

1. 49. The Laplace Transform is a powerful tool used in circuit analysis for:

   • A. Solving differential equations
   • B. Analyzing only DC circuits
   • C. Finding instantaneous values
   • D. Plotting waveforms

2. 50. What is "time constant" of an RC circuit?

   • A. The time it takes for the capacitor to fully charge
   • B. The time it takes for the capacitor voltage to reach approximately 63.2% of its final value
   • C. The time it takes for the capacitor to discharge completely
   • D. The time it takes for the current to reach its maximum

3. 51. What is "time constant" of an RL circuit?

   • A. The time it takes for the inductor to fully discharge
   • B. The time it takes for the current in the inductor to reach approximately 63.2% of its final value
   • C. The time it takes for the voltage across the inductor to become zero
   • D. The time it takes for the circuit to resonate

4. 52. The unit of magnetic flux is:

   • A. Tesla
   • B. Weber
   • C. Henry
   • D. Ampere

5. 53. The unit of magnetic flux density is:

   • A. Weber
   • B. Henry
   • C. Tesla
   • D. Ampere

6. 54. What is "reluctance" in a magnetic circuit?

   • A. The opposition to the establishment of magnetic flux
   • B. The ease with which magnetic flux is established
   • C. The magnetic field strength
   • D. The current flowing

7. 55. The unit of reluctance is:

   • A. Henry
   • B. Ampere-turns/Weber
   • C. Weber
   • D. Tesla

8. 56. What is "permeability"?

   • A. The ability of a material to oppose magnetic flux
   • B. The ability of a material to support the formation of a magnetic field
   • C. The strength of a magnetic field
   • D. The current flowing through a coil

9. 57. Lenz's Law states that the direction of induced current is such that it:

   • A. Opposes the change in magnetic flux that produced it
   • B. Aids the change in magnetic flux that produced it
   • C. Is independent of magnetic flux
   • D. Is always in the direction of the magnetic field

10. 58. Faraday's Law of Electromagnetic Induction states that the magnitude of induced EMF is proportional to:

    • A. The rate of change of magnetic flux linkage
    • B. The magnetic field strength
    • C. The current
    • D. The resistance

11. 59. What is "power factor correction"?

    • A. Increasing reactive power
    • B. Improving the power factor of an AC power system closer to 1
    • C. Decreasing real power
    • D. Increasing apparent power

12. 60. The "form factor" of an AC waveform is the ratio of:

    • A. Peak value to RMS value
    • B. RMS value to average value
    • C. Average value to peak value
    • D. Peak value to average value