When cooled below \(4.2\) K, mercury becomes a superconductor, which means it has no electrical resistance. When a current is passed through mercury under these conditions, which one of the following effects will be present?
(a) thermal
(b) chemical
(c) magnetic
Choose the correct option from the given ones:
1. | (a) and (c) only |
2. | (a), (b) and (c) |
3. | (b) only |
4. | (c) only |
i. | \(A\) is feebly repelled. |
ii. | \(B\) is feebly attracted. |
iii. | \(C\) is strongly attracted. |
iv. | \(D\) remains unaffected. |
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. |
Statement I: | All paramagnetic substances become diamagnetic as their temperature is lowered. |
Statement II: | All ferromagnetic substances become paramagnetic when their temperature is lowered. |
1. | Statement I is incorrect and Statement II is correct. |
2. | Both Statement I and Statement II are correct. |
3. | Both Statement I and Statement II are incorrect. |
4. | Statement I is correct and Statement II is incorrect. |
Soft iron is used to manufacture electromagnets because:
1. It has a high permeability.
2. Its retentivity and coercivity are small.
3. Its retentivity and coercivity are high.
4. Both (1) & (2)
1. | low hysteresis loss | 2. | high hysteresis loss |
3. | high permeability | 4. | both (1) and (3) |