# Gibilisco: MCQ in Inductance | ECE Board Exam

(Last Updated On: March 16, 2020) This is the Multiple Choice Questions (MCQs) in Chapter 10: Inductance from the book Teach Yourself Electricity and Electronics, 5th edition by Stan Gibilisco. If you are looking for a reviewer in Electronics Engineering this will definitely help you before taking the Board Exam.

### Start Practice Exam Test Questions

1. An inductor works by:

• A. Charging a piece of wire.
• B. Storing energy as a magnetic field.
• C. Choking off high-frequency ac.
• D. Introducing resistance into a circuit.

2. Which of the following does not affect the inductance of a coil?

• A. The diameter of the wire.
• B. The number of turns.
• C. The type of core material.
• D. The length of the coil.

3. In a small inductance:

• A. Energy is stored and released slowly.
• B. The current flow is always large.
• C. The current flow is always small.
• D. Energy is stored and released quickly.

4. A ferromagnetic core is placed in an inductor mainly to:

• A. Increase the current carrying capacity.
• B. Increase the inductance.
• C. Limit the current.
• D. Reduce the inductance.

5. Inductors in series, assuming there is no mutual inductance, combine:

• A. Like resistors in parallel.
• B. Like resistors in series.
• C. Like batteries in series with opposite polarities.
• D. In a way unlike any other type of component.

6. Two inductors are connected in series, without mutual inductance. Their values are 33 mH and 55 mH. The net inductance of the combination is:

• A. 1.8 H.
• B. 22 mH.
• C. 88 mH.
• D. 21 mH.

7. If the same two inductors (33 mH and 55 mH) are connected in parallel without mutual inductance, the combination will have a value of:

• A. 1.8 H.
• B. 22 mH.
• C. 88 mH.
• D. 21 mH.

8. Three inductors are connected in series without mutual inductance. Their values are 4 nH, 140 μH, and 5 H. For practical purposes, the net inductance will be very close to:

• A. 4 nH.
• B. 140 μH.
• C. 5 H.
• D. None of these.

9. Suppose the three inductors mentioned above are connected in parallel without mutual inductance. The net inductance will be close to:

• A. 4 nH.
• B. 140 μH.
• C. 5 H.
• D. None of these.

10. Two inductors, each of 100 μH, are in series. The coefficient of coupling is 0.40. The net inductance, if the coil fields reinforce each other, is:

• A. 50 μH.
• B. 120 μH.
• C. 200 μH.
• D. 280 μH.

11. If the coil fields oppose in the foregoing series-connected arrangement, the net inductance is:

• A. 50 μH.
• B. 120 μH.
• C. 200 μH.
• D. 280 μH.

12. Two inductors, having values of 44 mH and 88 mH, are connected in series with a coefficient of coupling equal to 1.0 (maximum possible mutual inductance). If their fields reinforce, the net inductance (to two significant digits) is:

• A. 7.5 mH.
• B. 132 mH.
• C. 190 mH.
• D. 260 mH.

13. If the fields in the previous situation oppose, the net inductance will be:

• A. 7.5 mH.
• B. 132 mH.
• C. 190 mH.
• D. 260 mH.

14. With permeability tuning, moving the core further into a solenoidal coil:

• A. Increases the inductance.
• B. Reduces the inductance
• C. Has no effect on the inductance, but increases the current-carrying capacity of the coil.
• D. Raises the frequency.

15. A significant advantage, in some situations, of a toroidal coil over a solenoid is:

• A. The toroid is easier to wind.
• B. The solenoid cannot carry as much current.
• C. The toroid is easier to tune.
• D. The magnetic flux in a toroid is practically all within the core.

16. A major feature of a pot-core winding is:

• A. High current capacity.
• B. Large inductance in small volume.
• C. Efficiency at very high frequencies.
• D. Ease of inductance adjustment.

17. As an inductor core material, air:

• A. Has excellent efficiency.
• B. Has high permeability.
• C. Allows large inductance in a small volume.
• D. Has permeability that can vary over a wide range.

18. At a frequency of 400 Hz, the most likely form for an inductor would be:

• A. Air-core.
• B. Solenoidal.
• C. Toroidal.
• D. Transmission-line.

19. At a frequency of 95 MHz, the best form for an inductor would be:

• A. Air-core.
• B. Pot core.
• C. Either of the above.
• D. Neither of the above.

20. A transmission-line inductor made from coaxial cable, having velocity factor of 0.66, and working at 450 MHz, would be shorter than:

• A. 16.7 m.
• B. 11 m.
• C. 16.7 cm.
• D. 11 cm.