Magnetism and Matter

If a diamagnetic substance is brought near the north or the south pole of a bar magnet, it is

1. repelled by the north pole and attracted by the south pole
2. attracted by the north pole and repelled by the south pole
3. attracted by both the poles
4. repelled by both the poles

A bar magnet having a magnetic moment of 2 104 J T-1 is free to rotate in a horizontal plane. A horizontal magnetic field B = 6 10-4 T exists in the space. The work done in taking the magnet slowly from a direction parallel to the field to a direction 60 from the field is

1. 12 J
2. 6 J
3. 2 J
4. 0.6 J

Curie temperature above which

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

Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show

1. anti ferromagnetism
2. no magnetic property
3. diamagnetism
4. paramagnetism

Curie temperature is the temperature above which

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

If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by d, p and f respectively, then

1. d = 0 and p 0
2. d 0 and p = 0
3. p = 0 and f 0
4. d 0 and f 0

A diamagnetic material in a magnetic field moves

1. from stronger to the weaker parts of the field
2. from weaker to the stronger parts of the field
3. perpendicular to the field
4. in none of the above directions

According to Curie's law, the magnetic susceptibility of a substance at an absolute temperature T is proportional to

1. 1/T
2. T
3. 1/T2
4. T2

A bar magnet is oscillating in the Earth's magnetic field with a period T. What happens to its period and motion if its mass is quadrupled?

1. motion remains simple harmonic with time period = T2
2. motion remains S.H.M. with time period = 2T
3. motion remains S.H.M. with time period = 4T
4. motion remains S.H.M. and period remains nearly constant

Two bar magnets having same geometry with magnetic moments M and 2M, are firstly placed in such a way that their similar poles are same side then its time period of oscillation is T1. Now the polarity of one of the magnets is reversed then time period of oscillation is T2, then

1. T1 < T2
2. T1 = T2
3. T1 > T2
4. T2 =