Circuit Theory – Multiple Choice Questions (MCQs)

1. 157. 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

2. 158. 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

3. 159. 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

4. 160. 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

5. 161. The "peak factor" (or crest factor) of an AC waveform is the ratio of:

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

6. 162. What is "active power"?

   • A. The power consumed by reactive components
   • B. The actual power consumed or dissipated in an AC circuit
   • C. The power generated by the source
   • D. The apparent power

7. 163. The unit of active power is:

   • A. VAR (Volt-Ampere Reactive)
   • B. VA (Volt-Ampere)
   • C. Watt
   • D. Joule

8. 164. What is "reactive power"?

   • A. The power dissipated in resistors
   • B. The power that oscillates between the source and reactive components
   • C. The actual power consumed
   • D. The total power

9. 165. The unit of reactive power is:

   • A. Watt
   • B. VA
   • C. VAR
   • D. Joule

10. 166. What is "apparent power"?

    • A. The power dissipated in resistors
    • B. The vector sum of active power and reactive power
    • C. The power consumed by reactive components
    • D. The actual power consumed

11. 167. The unit of apparent power is:

    • A. Watt
    • B. VAR
    • C. VA
    • D. Joule

12. 168. The "reciprocity theorem" applies to:

    • A. Non-linear circuits
    • B. Active circuits
    • C. Linear and bilateral circuits
    • D. Unilateral circuits