The magnetic moment of a magnet \((10 ~\text{cm}\times 4~\text{cm}\times1~\text{cm})\) is \(4 ~\text{Am}^2\). Its intensity of magnetisation is:
1. \(10^{3}\) A/m
2. \(10^{2}\) A/m
3. \(10^{5}\) A/m
4. \(10^{4}\) A/m
1. | \(9~\text{gauss}\) | 2. | \(4~\text{gauss}\) |
3. | \(36~\text{gauss}\) | 4. | \(4.5~\text{gauss}\) |
The magnetization of a piece of iron or steel:
1. | depends on the strength of the magnetizing field. |
2. | depends on external conditions such as temperature. |
3. | cannot be done beyond the saturation point. |
4. | all of these. |
A Gaussian surface is drawn enclosing the N-pole of a bar magnet. The net magnetic flux through the Gaussian surface will be:
(pole strength of N-pole is treated as positive and S-pole as negative)
1. | positive. |
2. | negative. |
3. | positive or negative. |
4. | zero. |
Choose the correct statement regarding magnetism.
1. | Paramagnetic sample displays greater magnetization when cooled. |
2. | Diamagnetism is almost independent of temperature. |
3. | Ferromagnetic substances show hysteresis. |
4. | All of these. |
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 |
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 |
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. | \(OA\) |
The variation of magnetic susceptibility with temperature for a diamagnetic substance is best represented by:
1. | ![]() |
2. | ![]() |
3. | ![]() |
4. | ![]() |
A uniform magnetic field, parallel to the plane of the paper existed in space initially directed from left to right. When a bar of soft iron is placed in the field parallel to it, the lines of force passing through it will be represented by:
1. | 2. | ||
3. | 4. |