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. | \(Q \over 2\varepsilon_0r\) |
1. | can not be defined as \(-\int_{A}^{B} { \vec E\cdot \vec{dl}}\) |
2. | must be defined as \(-\int_{A}^{B} {\vec E\cdot \vec{dl}}\) |
3. | is zero |
4. | can have a non-zero value. |
1. | The electric potential at the surface of the cube is zero. |
2. | The electric potential within the cube is zero. |
3. | The electric field is normal to the surface of the cube. |
4. | The electric field varies within the cube. |
a. | in all space |
b. | for any \(x\) for a given \(z\) |
c. | for any \(y\) for a given \(z\) |
d. | on the \(x\text-y\) 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 the figure. The electric field at points \(A\), \(B\) and \(C\) are respectively:
1. | \(1~\text{V/cm}, \frac{1}{2} ~\text{V/cm}, 2~\text{V/cm} \text { (all along +ve X-axis) }\) |
2. | \(1~\text{V/cm}, \frac{1}{2} ~\text{V/cm}, 2 ~\text{V/cm} \text { (all along -ve X-axis) }\) |
3. | \(\frac{1}{2} ~\text{V/cm}, 1~\text{V/cm}, 2 ~\text{V/cm} \text { (all along +ve X-axis) }\) |
4. | \(\frac{1}{2}~\text{V/cm}, 1~\text{V/cm}, 2 ~\text{V/cm} \text { (all along -ve X-axis) }\) |