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 \(C\) |
If H is the horizontal component of the earth's magnetic field and 'V' is the vertical component of the earth's magnetic field, then at the magnetic equator:
1. V and H are equal.
2. values of V and H are zero.
3. value of H is zero only.
4. value of V is zero only.
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 \(\chi\) of a diamagnetic material depends on absolute temperature \(T\) as:
1. \(\chi \propto T\)
2. \(\chi \propto \frac{1}{T}\)
3. \(\chi \propto T^0\)
4. \(\chi \propto \frac{1}{\sqrt{T}}\)
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 |
An electric cable is carrying current from north to south. The position of the null point from the cable is:
1. Vertically upward
2. Vertically downward
3. Eastward
4. Nowhere
Which of the following graphs represents the correct variation of the intensity of magnetisation (I) with the intensity of the magnetising field (H) in a ferromagnetic substance?
1. | 2. | ||
3. | 4. |