On rotating a point charge having a charge \(q\) around a charge \(Q\) in a circle of radius \(r\), the work done will be:
1. | \(q \times2 \pi r\) | 2. | \(q \times2 \pi Q \over r\) |
3. | zero | 4. | \(Q \over 2\varepsilon_0r\) |
The work done to move a charge along an equipotential from A to B:
1. | can not be defined as \(-\int_{\mathrm{A}}^{\mathrm{B}} \text { E. dl. }\) |
2. | must be defined as \(-\int_{\mathrm{A}}^{\mathrm{B}} \text { E. dl. }\) |
3. | is zero |
4. | can have a non-zero value. |
A cube of a metal is given a positive charge Q. For the above system, which of the following statements is true?
1. | Electric potential at the surface of the cube is zero. |
2. | Electric potential within the cube is zero. |
3. | Electric field is normal to the surface of the cube. |
4. | Electric field varies within the cube. |
Consider a uniform electric field in the Z-direction. The potential is constant:
a. | in all space |
b. | for any x for a given z |
c. | for any y for a given z |
d. | on the x-y plane for a given z |
1. | (a, b, c) | 2. | (a, c, d) |
3. | (b, c, d) | 4. | (c, d) |
Some equipotential surfaces are shown in figure. The electric field at points A, B and C are respectively:
1. | \(1 \mathrm{~V} / \mathrm{cm}, \frac{1}{2} \mathrm{~V} / \mathrm{cm}, 2 \mathrm{~V} / \mathrm{cm} \text { (all along +ve X-axis) }\) |
2. | \(1 \mathrm{~V} / \mathrm{cm}, \frac{1}{2} \mathrm{~V} / \mathrm{cm}, 2 \mathrm{~V} / \mathrm{cm} \text { (all along -ve X-axis) }\) |
3. | \(\frac{1}{2} \mathrm{~V} / \mathrm{cm}, 1 \mathrm{~V} / \mathrm{cm}, 2 \mathrm{~V} / \mathrm{cm} \text { (all along +ve X-axis) }\) |
4. | \(\frac{1}{2} \mathrm{~V} / \mathrm{cm}, 1 \mathrm{~V} / \mathrm{cm}, 2 \mathrm{~V} / \mathrm{cm} \text { (all along -ve X-axis) }\) |