1. | a force along \(+y\) axis only. |
2. | a force along \(-y\) axis. |
3. | zero force, but a torque. |
4. | no force and no torque. |
Assertion (A): | Work done by magnetic force on a charged particle moving in a uniform magnetic field is zero. |
Reason (R): | Path of a charged particle in a uniform magnetic field, projected in the direction of field, will be a straight line. |
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. |
1. | \( \dfrac{\mu_{0} i}{2 \pi a}(\hat{i}+\hat{j})\) | 2. | \( \dfrac{\mu_{0} i}{2 \pi a}(-\hat{i}+\hat{j})\) |
3. | \(\dfrac{\mu_{0} i}{2 \pi a}(-\hat{i}-\hat{j})\) | 4. | \(\dfrac{\mu_{0} i}{2 \pi a}(\hat{i}-\hat{j})\) |
Which of the following statements about a moving coil galvanometer is incorrect?
1. | The spring in a galvanometer provides a counter torque that balances the magnetic torque. |
2. | A galvanometer has multiple turns of wire to enhance the torque acting on the coil. |
3. | In all positions, the magnetic field \(B\) remains parallel to the plane of the coil. |
4. | The deflection \(\phi\) indicated by the scale is proportional to the square of the current flowing through the coil. |
To ensure that the magnetic field is radial in a moving coil galvanometer:
1. | The number of turns in the coil is increased. |
2. | The magnet is taken in the form of a horse-shoe. |
3. | The poles are cut cylindrically. |
4. | The coil is wound on an aluminum frame. |
1. | zero | 2. | \(2\pi r i B\) |
3. | \(\pi r^2i B\) | 4. | \(2\pi r^2i B\) |
1. | \(\dfrac{\mu_{0} I}{6}\) | 2. | \(\dfrac{2 \mu_{0} I}{6}\) |
3. | \(\dfrac{4\mu_{0} I}{6}\) | 4. | \(\dfrac{5\mu_{0} I}{6}\) |
1. | attract each other. |
2. | repel each other. |
3. | exert no force on each other, but exert a torque. |
4. | neither exert any force nor any torque on each other. |