Magnetic Materials MCQ

1. The coercive force of ALNICO is

  1. 44000 A/m
  2. 40 A/m
  3. 4 A/m
  4. 0.16 A/m
Answer
Answer. a

2. Magnetic moment is the

  1. Pole strength
  2. Vector quantity
  3. Scalar quantity
  4. Universal constant
Answer
Answer. b

3. Magnets of low retentivity but high permeability are called

  1. Electromagnets
  2. Permanent magnets
  3. Weak magnets
  4. One pole magnets
Answer
Answer. a

4. A permanent magnet will not attract

  1. Steel
  2. Nickel
  3. Aluminium
  4. Copper
Answer
Answer. d

5. Which of the following is diamagnetic?

  1. MgO
  2. BaTiO3
  3. Cobalt
  4. Copper
Answer
Answer. d

6. Material which takes permanent magnetic dipoles is known as

  1. Paramagnetic
  2. Diamagnetic
  3. Ferromagnetic
  4. Ferrimagnetic
Answer
Answer. c

7. Silicon content in iron lamination is kept within 5% as it

  1. Makes the material brittle
  2. Reduces the curie point
  3. Increases hysteresis loss
  4. Increases cost
Answer
Answer. a

8. Ferrite cores are used in high-frequency transformer because it has

  1. Average permeability
  2. Low hysteresis
  3. Low impedance
  4. High resistance
Answer
Answer. d

9. The iron core material used at high frequencies in radio circuits is

  1. Ferrite
  2. Material of low permeability
  3. Material of high permeability
  4. A material which reduces inductance as well as losses
Answer
Answer. a

10. Reluctance offered by the magnetic circuit depends upon

  1. Nature of magnetic material
  2. Length of magnetic flux path
  3. Cross-sectional area of the material
  4. All options are correct
Answer
Answer. d

11. The relative permeability of paramagnetic material is

  1. Less than unity
  2. Equal to unity
  3. Greater than unity
  4. None of these
Answer
Answer. c

12. The relative permeability of a material is 0.95. The material is

  1. Diamagnetic
  2. Paramagnetic
  3. Ferromagnetic
  4. None of these
Answer
Answer. a

13. The materials having low retentivity are suitable for making

  1. Temporary magnets
  2. Permanent magnets
  3. Weak magnets
  4. None of these
Answer
Answer. a

14. Susceptibility for paramagnetic materials is

  1. Positive and small
  2. Negative and small
  3. Positive and large
  4. Negative and large
Answer
Answer. a

15. Metallic copper is a

  1. Paramagnetic substance
  2. Diamagnetic substance
  3. Ferromagnetic substance
  4. Ferrimagnetic substance
Answer
Answer. b

16. The relative permeability of the superconductor materials is

  1. 0
  2. 1
  3. −1
  4. infinity
Answer
Answer. a
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