# Class 12th Physics Chapter 5 Magnetism & Matter VVI Objective Question

Magnetism And Matter

1. SI unit of magnetic flux is :

(A) Ohm

(B) Weber

(C) Tesla

(D) None of these

2. Copper is

(A) Paramagnetic

(B) Ferromagnetic

(C) Diamagnetic

(D) Semi-conductor

3. Which of the following has greater susceptibility ?

(A) Paramagnetic

(B) Diamagnetic

(C) Ferromagnetic

(D) Semi-conductor

4. If a magnet is kept in magnetic meridian with its North pole pointing north, then number of neutral points will be :

(A) 1

(B) 2

(C) 3

(D) None of these

5. Which is more appropriate material for a strong electromagnet?

(A) air

(B) soft iron

(C) steel

(D) alloy of copper and nickel

6. Liquid and gases are

(A) ferromagnetic

(B) diamagnetic

(C) paramagnetic

(D) behave magnetically like a vacuum

7. Which of the following materials has magnetic susceptibility negative and less than 1 in value ?

(A) ferromagnetic

(B) paramagnetic

(C) diamagnetic

(D) None of these

8. The magnetic susceptibility of paramagnetic substances is

(A) constant

(B) zero

(C) infinity

(D) dependent upon magnetic field

9. Nickel is

(A) diamagnetic

(B) paramagnetic

(C) ferromagnetic

(D) None of these

10. The distance between the two poles of a magnet is called

(A) magnetic length

(B) magnetic field

(C) magnetic axis

(D) magnetic moment

11. A magnet needle placed in a non-uniform magnetic field can experience

(A) a force and a torque

(B) a force but not a torque

(C) a torque but not a force

(D) None of these

12. The source of magnetism of a magnet is

(A) spin of electron

(B) cosmic rays

(C) presence of a big magnet inside the Earth

(D) the earth

13. Which should be small for a permanent magnet ?

(A) retentivity

(B) coercivity

(C) both (A) and (B)

(D) None of these

14. Iron is ferromagnetic

(A) at all temperature

(B) at NTP only

(C) above 770°C

(D) below 770°C

15. The magnetic susceptibility of air is

(A) positive

(B) negative

(C) zero

(D) positive or negative

16. Which of the following is diamagnetic?

(A) Na

(B) Ca

(C) O2(STP)

(D) N2(STP)

17. The magnetic induction at a distance r from a single pole is inversely proportional to

(A) r

(B) r2

(C) 1 / r

(D) 1 / r2

18. The work done in rotating a bar magnet of magnetic moment M in a magnetic field B by an angle θ from stable equilibrium is

(A) MB sinθ

(B) MB cosθ

(C) MB (1 – cosθ)

(D) MB (1 – sinθ)

19. The unit of magnetic potential is

(A) J Am

(B) JA-1m-1

(C) JA-1m-2

(D) JA2m-2

20. The value of permeability of a vaccum is

(A) 4π x 10-7 henry/meter

(B) 4π x 10-9 henry/meter

(C) 4π x 10-7 henry/meter

(D) 4π x 107 henry/meter

21. The value of dip at the pole of the earth is

(A) 0°

(B) 90°

(C) 45°

(D) 180°

22. A freely suspended needle at equator of the Earth

(A) remains vertical

(B) is inclined at 45°

(C) remains horizontal

(D) is inclined at 60°

23. For making an electromagnet, core material should have

(A) high magnetic susceptibility

(B) high magnetic retentivity

(C) high hysteris area

(D) None of these

24. A bar magnet of magnetic moment M is cut into two parts of equal length. The magnetic moment of either part is

(A) M

(B) M/2

(C) 2M

(D) Zero

25. Magnetic dipole moment is a vector quantity directed from: .

(A) South to North Pole

(B) North to South Pole

(C) East to West direction

(D) West to East direction