1. | reducing relative motion between the core and magnet in an electric motor |
2. | by making the core of thin laminations |
3. | by increasing the conductor cross-sectional area |
4. | both (1) and (2) are correct |
Assertion (A): | A bar magnet is dropped into a long vertical copper tube. Even taking air resistance as negligible, the magnet attains a constant terminal velocity. If the tube is heated, the terminal velocity gets increased. |
Reason (R): | The terminal velocity does not depend on eddy current produced in copper tube. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
The slotting processes in a metallic sheet results in:
1. | The increase of the resistance in the path for circulation of current. |
2. | Decrease in the strength of eddy current. |
3. | A feeble in the electromagnetic damping. |
4. | All of these |
Assertion (A): | Iron loss is minimized by using a laminated core. |
Reason (R): | Lamination of core restricts eddy current. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |