Magnetic Materials MCQ | Objective Question with Answer for Magnetic Materials

16. Materials in which the permanent dipoles interact with each other so heavily that they tend to align parallel to each other are called

• (a) Ferromagnetic
• (b) Ferrimagnetic
• (c) Paramagnetic
• (d) Anti-ferromagnetic

17. The temperature above which an antiferromagnetic material becomes paramagnetic is called

• (a) Neel temperature
• (b) Peak temperature
• (c) Critical temperature
• (d) Weiss temperature

18. The relative permeability is less than 1 in

• (a) ferromagnetic materials
• (b) diamagnetic materials
• (c) paramagnetic materials
• (d) ferrites

19. As per curie-Weiss law, the magnetic susceptibility of a material varies as

• (a) T^-2
• (b) 1/T
• (c) T
• (d) T²

20. Ferrites have

• (a) low copper loss
• (b) low eddy current loss
• (c) low resistivity
• (d) higher specific gravity than that of the iron

21. The relationship between relative permeability \mu_rand magnetic susceptibility (\chi)of the medium is

• (a) \mu_r=1+\chi
• (b) \mu_r= \frac{1}{1+\chi}
• (c) \mu_r= 1-\chi
• (d) \mu_r= \frac{1}{\chi}

22. Ferromagnetic property may be explained on the basis of

• (a) Faraday’s theory
• (b) Curie-Weiss theory
• (c) Domain theory
• (d) Einstein’s theory

23. Soft iron is characterized by the saturation magnetization M_s, coercivity H_c, and retentivity B_c. it is suitable for electromagnetic because

• (a) M_s, H_c, and Bc are small
• (b) Ms is small, Hc and Bc are large
• (c) Ms is large, Hc and Bc are small
• (d) Ms, Hc, and B_c are large

24. Diamangetic susceptibility is very

• (a) small and negative
• (b) small and positive
• (c) large and negative
• (d) large and positive

25. Magnetostriction is the effect produced when a change of magnetic material results in

• (a) change of permeability
• (b) change in dimensions
• (c) change of temperature
• (d) change of magnetic field strength

26. Which of the following magnetic materials has the highest reluctance?

• (a) Ferromagnetic
• (b) Paramagnetic
• (c) Diagmagnetic
• (d) None of the above

27. in ferrimagnetic materials, the net magnetic moment created due to magnetization by an applied field is

• (a) Normal to the applied field
• (b) Adds to the applied field
• (c) in line with magneto motive force
• (d) substrate from the applied field

28. At what temperature do domains lose their ferromagnetic properties?

• (a) Above ferromagnetic Curie temperature
• (b) below paramagnetic Curie temperature
• (c) Above 4^oK
• (d) At room temperature

29. When the working temperature becomes more than the curie temperature, a ferromagnetic material becomes a

• (a) diamagnetic material
• (b) paramagnetic material
• (c) ferromagnetic material
• (d) Mu-material

30. Compared to other materials, a material with a wider hysteresis loop has

• (a) Lower permeability, higher retentivity, and higher coercivity
• (b) higher permeability, lower retentivity, and higher coercivity
• (c) lower permeability, higher retentivity, and lower reluctance
• (b) lower permeability, lower retentivity, and lower residual magnetism

31. For elements of the iron group the net orbital dipole moment in the solid state is

• (a) zero
• (b) 10 – 20
• (c) 10000 – 12000
• (d) infinity