Magnetism - Gibilisco MCQs in Electronics

MCQs in Magnetism from the book Teach Yourself Electricity and Electronics, 5th edition by Stan Gibilisco.

Multiple choice questions in Magnetism

This is the Multiple Choice Questions (MCQs) in Chapter 8: Magnetism 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.

Begin the Test

1. The geomagnetic field:

  • A. Makes the earth like a huge horseshoe magnet.
  • B. Runs exactly through the geographic poles.
  • C. Is what makes a compass work.
  • D. Is what makes an electromagnet work.

2. Geomagnetic lines of flux:

  • A. Are horizontal at the geomagnetic equator.
  • B. Are vertical at the geomagnetic equator.
  • C. Are always slanted, no matter where you go.
  • D. Are exactly symmetrical around the earth, even far out into space.

3. A material that can be permanently magnetized is generally said to be:

  • A. Magnetic.
  • B. Electromagnetic.
  • C. Permanently magnetic.
  • D. Ferromagnetic.

4. The force between a magnet and a piece of ferromagnetic metal that has not been magnetized:

  • A. Can be either repulsive or attractive.
  • B. Is never repulsive.
  • C. Gets smaller as the magnet gets closer to the metal.
  • D. Depends on the geomagnetic field.

5. Magnetic flux can always be attributed to:

  • A. Ferromagnetic materials.
  • B. Aligned atoms.
  • C. Motion of charged particles.
  • D. The geomagnetic field.

6. Lines of magnetic flux are said to originate:

  • A. In atoms of ferromagnetic materials.
  • B. At a north magnetic pole.
  • C. Where the lines converge to a point.
  • D. In charge carriers.

7. The magnetic flux around a straight, current-carrying wire:

  • A. Gets stronger with increasing distance from the wire.
  • B. Is strongest near the wire.
  • C. Does not vary in strength with distance from the wire.
  • D. Consists of straight lines parallel to the wire.

8. The gauss is a unit of:

  • A. Overall magnetic field strength.
  • B. Ampere-turns.
  • C. Magnetic flux density.
  • D. Magnetic power.

9. A unit of overall magnetic field quantity is the:

  • A. Maxwell.
  • B. Gauss.
  • C. Tesla.
  • D. Ampere-turn.

10. If a wire coil has 10 turns and carries 500 mA of current, what is the magnetomotive force in ampere-turns?

  • A. 5000.
  • B. 50.
  • C. 5.0.
  • D. 0.02.

11. If a wire coil has 100 turns and carries 1.30 A of current, what is the magnetomotive force in gilberts?

  • A. 130.
  • B. 76.9.
  • C. 164.
  • D. 61.0.

12. Which of the following is not generally possible in a geomagnetic storm?

  • A. Charged particles streaming out from the sun.
  • B. Fluctuations in the earth’s magnetic field.
  • C. Disruption of electrical power transmission.
  • D. Disruption of microwave radio links.

13. An ac electromagnet:

  • A. Will attract only other magnetized objects.
  • B. Will attract pure, unmagnetized iron.
  • C. Will repel other magnetized objects.
  • D. Will either attract or repel permanent magnets, depending on the polarity.

14. An advantage of an electromagnet over a permanent magnet is that:

  • A. An electromagnet can be switched on and off.
  • B. An electromagnet does not have specific polarity.
  • C. An electromagnet requires no power source.
  • D. Permanent magnets must always be cylindrical.

15. A substance with high retentivity is best suited for making:

  • A. An ac electromagnet.
  • B. A dc electromagnet.
  • C. An electrostatic shield.
  • D. A permanent magnet.

16. A relay is connected into a circuit so that a device gets a signal only when the relay coil carries current. The relay is probably:

  • A. An ac relay.
  • B. A dc relay.
  • C. Normally closed.
  • D. Normally open.

17. A device that reverses magnetic field polarity to keep a dc motor rotating is:

  • A. A solenoid.
  • B. An armature coil.
  • C. A commutator.
  • D. A field coil.

18. A high tape-recorder motor speed is generally used for:

  • A. Voices.
  • B. Video.
  • C. Digital data.
  • D. All of the above.

19. An advantage of a magnetic disk, as compared with magnetic tape, for data storage and retrieval is that:

  • A. A disk lasts longer.
  • B. Data can be stored and retrieved more quickly with disks than with tapes.
  • C. Disks look better.
  • D. Disks are less susceptible to magnetic fields.

20. A bubble memory is best suited for:

  • A. A large computer.
  • B. A home video entertainment system.
  • C. A portable cassette player.
  • D. A magnetic disk.

Complete List of Multiple Choice Questions from this Book

Check your work.


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