Magnetism and Matter MCQs Quiz Multiple Choice Questions & Answers

1. Which of the following property shows the property of ferromagnetic substances?

1. The ferromagnetic property depends on tem- perature.
2. The ferromagnetic property does not depend on temperature.
3. At high enough temperature ferromagnet becomes a diamagnet.
4. At low temperature ferromagnet becomes a paramagnet.

2. Which of the following is responsible for the earth's magnetic field?

1. Convective currents in earth's core
2. Diversive current in earth's core.
3. Rotational motion of earth.
4. Translational motion of earth.

3. Which of the following is not showing the essential difference between electrostatic shielding by a conducting shell and magnetostatic shielding?

1. Electrostatic field lines can end on charges and conductors have free charges.
2. Magnetic field lines can end but conductors cannot end them.
3. Lines of magentic field cannot end on any material and perfect shielding is not possible.
4. Shells of high permeability materials can be used to divert lines of magnetic field from the interior region.

4. Which of the following is correct about magnetic monopole?

1. Magnetic monopole exist.
2. Magnetic monopole does not exist.
3. Magnetic monopole have constant value of monopole momentum.
4. The monopole momentum increase due to increase at its distance from the field.

5. Which of the following independent quantities is not used to specify the earth's magnetic field?

1. Magnetic declination (θ).
2. Magnetic dip.
3. Horizontal component of earth's field (BH).
4. Vertical component of earth's field (BV).

6. Which of the following has higher magnetic susceptibility?zdiamagnetic

1. paramagnetic
2. ferromagnetic
3. None of these

7. Which of the following has a low value in ferrites?

1. Conductivity
2. Permeability
3. Magnetic susceptibility
4. All the above

8. What is the angle of dip at a place where the horizontal component of earth's magnetic field is equal to the vertical component?

1. 0^o
2. 30^o
3. 45^o
4. 90^o

9. Three needles N1 N2 and N3 are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. A magnet, when brought close to them, will

1. attract N1 strongly, but repel N2 and N3 weakly.
2. attract all three of them.
3. attract N1 and N2 strongly but repel N3.
4. attract N1 strongly, N2 weakly and repel N3 weakly.

10. The vertical component of earth's magnetic field . at a place is sqrt(3) times the horizontal component the value of angle of dip at this place is

1. 30^o
2. 45^o
3. 60^o
4. 90^o

11. The strength of the earthcs magnetic field is

1. constant everywhere.
2. zero everywhere.
3. having very high value.
4. vary from place to place on the earth's surface.

12. The relation between geometric length (L) and magnetic length (L_m) is:

1. L_m = 56 L_g
2. L_m = 65 L_g
3. L_m = L_g
4. L_m = 2RY;UL L_g

13. The radius of curvature of the path of charged particle in a uniform magnetic file is directly proportional to the

1. charge on fie particle
2. Momentum of particle
3. energy of particle
4. Strength of field

14. The primary origin of magnetism lies in

1. atomic current and intrinsic spin of electrons.
2. polar and non polar nature of molecules.
3. pauli exclusion principle.
4. electronegative nature of materials.

15. The neutral point in the magnetic field of a horizontally placed bar magnet is a point where the magnetic field due to that bar magnet is:

1. zero
2. more than that of earth
3. less than that of earth
4. equal to that of earth

16. The net magnetic flux through any closed surface, kept in a magnetic field is

1. zero
2. μ04π
3. 4πμ0
4. 4μ0π

17. The material suitable for making electromagnets should have

1. high retentivity and high coercivity.
2. low retentivity and low coercivity.
3. high retentivity and low coercivity.
4. low retentivity and high coercivity.

18. The Mariner's compass is provided with Gimbals arrangement so as to :

1. keep the needle always horizontal
2. give a direct reading of declination
3. give the direct value of dip
4. all of the above

19. The magnetic lines of force inside a bar magnet:

1. do not exist
2. depends on area of cross-section of bar magnet
3. are from N-pole to S-pole of the magnet
4. are from S-pole to N-pole of the magnet.

20. The magnetic field strength due to a short bar magnet directed along its axial line at a distance r is B. What is its value at the same distance along the equatorial line?

1. B
2. 2B
3. B2
4. B4

21. The magnetic field of earth is due to:

1. induction effect of the sun
2. the presence of a large magnet at the centre of the earth
3. interaction of cosmic rays with the current of earth
4. motion and distribution of some material in an outside the earth

22. The magnetic field at the centre of a current carrying circular loop is B. If the radius of the loop is doubled keeping the current unchanged, the magnetic field at the centre of loop will become:

1. B2
2. B4
3. 2B
4. 4B

23. The force between two parallel wire 2 × 10^-7 Nm^-1, placed 1 m apart to each other in vacuum. The electric current flowing through the wires is:

1. 1 A
2. zero
3. 5 × 10⁶ A
4. 2 × 10^-7 A

24. The earth behaves as a magnet with magnetic field pointing approximately from the geographic

1. North to South
2. South to North
3. East to West
4. West to East

25. The dimensional representation of magnetic flux density is :

1. [MLT^-2]
2. [MLT^-2A^-1]
3. [MLT^-2A^-2]
4. [MT^-2A^-1]

26. The angle of dip at a certain place where the horizontal and vertical components of the earth's magnetic field are equal is

1. 30c
2. 75^o
3. 60^o
4. 45^o

27. Tangent law is applicable only when:

1. two uniform and mutually perpendicular magnetic fields exist
2. two magnetic fields exist
3. horizontal component of earth's magnetic field is present
4. uniform magnetic field are used

28. S.I. unit of flux is :

1. Ohm
2. Weber
3. Tesla
4. None

29. On quadrupling the moment of inertia of a magnet, its frequency of oscillation will become:

1. half
2. double
3. four times
4. one-fourth

30. Magnetic moment for solenoid and corresponding bar magnet is

1. equal for both
2. more for solenoid
3. more for bar magnet
4. none of these

31. Let the magnetic field on earth be modelled by that of a point magnetic dipole at the centre of earth. The angle of dip at a point on the geographical equator is

1. always zero
2. positive, negative or zero
3. unbounded
4. always negative

32. Let the magnetic field on earth be modelled by that of a point magnetic dipole at the centre of earth. The angle of dip at a point on the geographical equator

1. is always zero.
2. can be zero at specific points.
3. cannot be positive or negative.
4. is not bounded.

33. In a moving coil galvanometer, we use a radial magnetic field so that the galvanometer scale is :

1. exponential
2. linear
3. algebraic
4. logarithmic

34. In a bar magnet, magnetic lines of force z :

1. are produced only at north pole like rays of light from a bulb
2. starts from north pole and ends at the south pole
3. emerge in circular paths from the middle of the bar
4. run continuously through the bar and outside

35. Ferrites may be:

1. ant. ferromagnetic
2. ferromagnetic
3. ferrimagnetic
4. None of the above

36. Curie temperature is the temperature above which

1. a ferromagnetic material becomes paramagnetic.
2. a ferromagnetic material becomes diamagnetic.
3. a paramagnetic material becomes diamagnetic.
4. a paramagnetic material becomes ferromagnetic.

37. Curie law xT = constant, relating magnetic susceptibility (x) and absolute temperature (T) of magnetic substance is obeyed by

1. all magnetic substances.
2. paramagnetic substances.
3. diamagnetic substances.
4. ferromagnetic substances.

38. At a given place on earth's surface the horizontal component of earth's magnetic field is 2 × 10^3-5 T and resultant magnetic field is 4 × 10^3-5 T. The angle of dip at this place is

1. 30^o
2. 60^o
3. 90^o
4. 45^o

39. A wire of length I has a magnetic moment M. It is then bent into a semi-circular arc. The new magnetic moment is :

1. M
2. M.l.
3. 2Mπ
4. Mπ

40. A magnetic needle is kept in a non-uniform magnetic field. It experiences

1. a torque but not a force.
2. neither a force nor a torque.
3. a force and a torque.
4. a force but not a torque.

41. A magnetic dipole moment is a vector quantity directed from:

1. S to N
2. N to S
3. E to W
4. W to E

42. A current carrying power line carries current from west to east. What will be direction of magnetic field 1 meter above it?

1. N to S
2. S to N
3. E to W
4. W to E