The variation of the intensity of magnetisation (I) with respect to the magnetising field (H) in a diamagnetic substance is described by the graph:
1. | OD | 2. | OC |
3. | OB | 4. | OA |
There are four light-weight-rod samples; A, B, C, D separately suspended by threads. A bar magnet is slowly brought near each sample and the following observations are noted:
i. | A is feebly repelled |
ii. | B is feebly attracted |
iii. | C is strongly attracted |
iv. | D remains unaffected |
Which one of the following is true?
1. | C is of a diamagnetic material |
2. | D is of a ferromagnetic material |
3. | A is of a non-magnetic material |
4. | B is of a paramagnetic material |
If a diamagnetic substance is brought near the north or the south pole of a bar magnet, it is:
1. | repelled by both the poles |
2. | repelled by the north pole and attracted by the south pole |
3. | attracted by the north pole and repelled by the south pole |
4. | attracted by both the poles |
The magnetic dipoles in a diamagnetic material are represented, for three situations. The three situations differ in magnitude if a magnetic field is applied to the material. In which situation the magnetization of the material is the greatest:
1. A
2. B
3. C
4. equal in A, B, and C
Two bar magnets are held together tightly in a vibration magnetometer. When their like poles are together, they make 20 oscillations per minute and when their unlike poles are together, they make 8 oscillations per minute. The ratio of the magnetic dipole moments of two bar magnets is:
1. 29:21
2. 6:15
3. 1:6
4. 25:4
The magnetic susceptibility of a diamagnetic material depends on absolute temperature T as:
The magnetic lines of force inside a bar magnet are:
1. | from south to the north pole. |
2. | from north to the south pole. |
3. | not present. |
4. | intersecting each other. |
The material which is used to make permanent magnet has:
1. | High retentivity, low coercivity |
2. | Low retentivity, low coercivity |
3. | Low retentivity, high coercivity |
4. | High retentivity, high coercivity |
Which of the following is not dimensionless?
(where symbols stand for their usual meanings in magnetism)
1.
2.
3.
4.
The magnetic moment of a magnet \((10 ~cm\times 4~cm\times1~cm)\) is \(4 ~Am^2\). Its intensity of magnetisation is:
1. 103 A/m
2. 102 A/m
3. 105 A/m
4. 104 A/m