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Electrical Units – Gibilisco MCQs in Electronics

Multiple choice questions in Electrical Units

This is the Multiple Choice Questions (MCQs) in Chapter 2: Electrical Units 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.

Topic Outline for the Chapter 2 MCQs

  • The Volt
  • The Ampere
  • Resistance and the Ohm
  • Conductance and the Siemens
  • Power and the Watt
  • A Word about Notation/li>
  • Energy and the Watt-Hour
  • Alternating Current and the Hertz
  • Safety Considerations in Electrical Work
  • Magnetism
  • Magnetic Units
  • Other Energy Units

start Practice Exam Test Questions

1. A positive electric pole:

  • A. Has a deficiency of electrons.
  • B. Has fewer electrons than the negative pole.
  • C. Has an excess of electrons.
  • D. Has more electrons than the negative pole

2. An EMF of one volt:

  • A. Cannot drive much current through a circuit.
  • B. Represents a low resistance.
  • C. Can sometimes produce a large current.
  • D. Drops to zero in a short time.

3. A potentially lethal electric current is on the order of:

  • A. 0.01 mA.
  • B. 0.1 mA.
  • C. 1 mA.
  • D. 0.1 A.

4. A current of 25 A is most likely drawn by:

  • A. A flashlight bulb.
  • B. A typical household.
  • C. A power plant.
  • D. A clock radio.

5. A piece of wire has a conductance of 20 siemens. Its resistance is:

  • A. 20 Ω.
  • B. 0.5 Ω.
  • C. 0.05 Ω.
  • D. 0.02 Ω.

6. A resistor has a value of 300 ohms. Its conductance is:

  • A. 3.33 millisiemens.
  • B. 33.3 millisiemens.
  • C. 333 microsiemens.
  • D. 0.333 siemens.

7. A mile of wire has a conductance of 0.6 siemens. Then three miles of the same wire has a conductance of:

  • A. 1.8 siemens.
  • B. 1.8 Ω.
  • C. 0.2 siemens.
  • D. Not enough information has been given to answer this.

8. A 2-kW generator will deliver approximately how much current, reliably, at 117 V?

  • A. 17 mA.
  • B. 234 mA.
  • C. 17 A.
  • D. 234 A.

9. A circuit breaker is rated for 15 A at 117 V. This represents approximately how many kilowatts?

  • A. 1.76.
  • B. 1760.
  • C. 7.8.
  • D. 0.0078.

10. You are told that a certain air conditioner is rated at 500 Btu. What is this in kWh?

  • A. 147.
  • B. 14.7.
  • C. 1.47.
  • D. 0.147.

11. Of the following energy units, the one most often used to define electrical energy is:

  • A. The Btu.
  • B. The erg.
  • C. The foot pound.
  • D. The kilowatt hour.

12. The frequency of common household ac in the U.S. is:

  • A. 60 Hz.
  • B. 120 Hz.
  • C. 50 Hz.
  • D. 100 Hz.

13. Half-wave rectification means that:

  • A. Half of the ac wave is inverted.
  • B. Half of the ac wave is chopped off.
  • C. The whole wave is inverted.
  • D. The effective value is half the peak value.

14. In the output of a half-wave rectifier:

  • A. Half of the wave is inverted.
  • B. The effective value is less than that of the original ac wave.
  • C. The effective value is the same as that of the original ac wave.
  • D. The effective value is more than that of the original ac wave.

15. In the output of a full-wave rectifier:

  • A. The whole wave is inverted.
  • B. The effective value is less than that of the original ac wave.
  • C. The effective value is the same as that of the original ac wave.
  • D. The effective value is more than that of the original ac wave.

16. A low voltage, such as 12 V:

  • A. Is never dangerous.
  • B. Is always dangerous.
  • C. Is dangerous if it is ac, but not if it is dc.
  • D. Can be dangerous under certain conditions.

17. Which of these can represent magnetomotive force?

  • A. The volt-turn.
  • B. The ampere-turn.
  • C. The gauss.
  • D. The gauss-turn.

18. Which of the following units can represent magnetic flux density?

  • A. The volt-turn.
  • B. The ampere-turn.
  • C. The gauss.
  • D. The gauss-turn.

19. A ferromagnetic material:

  • A. Concentrates magnetic flux lines within itself.
  • B. Increases the total magnetomotive force around a current-carrying wire.
  • C. Causes an increase in the current in a wire.
  • D. Increases the number of ampere-turns in a wire.

20. A coil has 500 turns and carries 75 mA of current. The magnetomotive force will be:

  • A. 37,500 At.
  • B. 375 At.
  • C. 37.5 At.
  • D. 3.75 At.

Complete List of Multiple Choice Questions from this Book

Check your work.

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