Determination of B/H Characteristic MCQ [Free PDF] – Objective Question Answer for Determination of B/H Characteristic Quiz

21. What is the unit for relative permeability?

A. H-m
B. H/m
C. H2/m
D. No unit

Answer: D

Relative permeability is the ratio of permeability of the material to the permeability of free space. Since it is a ratio, it does not have any units.

 

22. Which of the following expressions is correct with respect to relative permeability?

A. B = µrµ0/H
B. B = µrµ0H
C. B = µr0H
D. B = µrµ0/H2

Answer: B

For a non-magnetic material: B = µ0H. Hence for a material having a relative permeability

µr, B = µrµ0H.

 

23. A substance whose relative permeability is less than the permeability of free space is?

A. Diamagnetic
B. Paramagnetic
C. Ferromagnetic
D. Not a magnetic substance

Answer: A

A diamagnetic material creates a magnetic field opposing that of the external magnetic field and it repels the external magnetic field. Hence its relative permeability is less than that of the free space.

 

24. A substance whose relative permeability is more than the permeability of free space is?

A. Diamagnetic
B. Paramagnetic
C. Ferromagnetic
D. Both paramagnetic and ferromagnetic

Answer: D

Relative permeability = 1+Magnetic susceptibility

Since both paramagnetic and ferromagnetic materials have positive susceptibility, their relative permeability is greater than unity i.e. their permeability is more than the permeability of free space.

 

25. Diamagnetic substances have relative permeability_____________

A. Greater than 1
B. Less than 1
C. Equal to 1
D. Zero

Answer: B

A diamagnetic material creates a magnetic field opposing that of the external magnetic field and it repels the external magnetic field. Hence it has a relative permeability of less than 1.

 

26. Paramagnetic substances have relative permeability_____________

A. Greater than 1
B. Less than 1
C. Equal to 1
D. Zero

Answer: A

A paramagnetic material creates a magnetic field that is weakly attracted to that of the external magnetic field. Hence it has relative permeability greater than 1.

 

27. As the temperature increases up to the Curie temperature, the relative susceptibility of ferromagnetic materials?

A. Increases
B. Decreases
C. Remains constant
D. Becomes zero

Answer: A

The susceptibility of ferromagnetic materials increases with the increase in temperature and then it decreases when the temperature goes beyond the Curie temperature.

 

28. As the temperature increases beyond the Curie temperature, the relative susceptibility of ferromagnetic materials?

A. Increases
B. Decreases
C. Remains constant
D. Becomes zero

Answer: B

The susceptibility of ferromagnetic materials increases with the increase in temperature and then it decreases when the temperature goes beyond the curie temperature.

 

29. Reciprocal of reluctance is __________

A. Permeance
B. Susceptibility
C. Resistance
D. Conductance

Answer: A

The reciprocal of reactance is permeance. It is the ability of a material to allow the passage of magnetic lines of flux.

 

30. Reluctance is ________________ to the length of the material.

A. Directly proportional
B. Inversely proportional
C. Not related
D. Reluctance is ________________ to the length of the material.

Answer: A

The formula for reluctance is:

S = l/µ0 µr×A.

From the formula, we can see that reluctance is directly proportional to the length of the material.

Scroll to Top