Three charges \(-Q\), \(q\), and \(-2Q\) are placed along a line as shown in the figure. The system of charges will have a positive potential energy configuration when q is placed at midpoint of line joining \(-Q\) and \(-2Q\), if:
1. | \(q>{Q \over 3}\) | 2. | \(q<{Q \over 3}\) |
3. | \(q>{-Q \over 3}\) | 4. | \(q<{-Q \over 3}\) |
1. | If \(E\neq0,V\) cannot be zero |
2. | If \(V\neq0, E\) cannot be zero |
3. | If \(V\) is constant and non-zero, \(E\) must be zero |
4. | If \(V=0,E\) must be zero |
Work done to carry a negatively charged body in direction of the electric field:
(assuming no other force is acting on the body)
1. | is always negative. | 2. | maybe negative. |
3. | is always positive. | 4. | maybe zero. |
Two concentric metallic spherical shells \(A\) and \(B\) of radii \(a\) and \(b\) respectively \((b>a)\) are arranged such that outer shell is earthed and inner shell is charged to \(Q\). Charge on the outer surface of outer shell will be:
1. \(- \frac{Q a}{b}\)
2. \(Q \left[1 - \frac{a}{b}\right]\)
3. \(-Q\)
4. zero
The equivalent capacitance across \(A\) and \(B\) in the given figure is:
1. \( \frac{3}{2}\text{C}\)
2. \(\text{C}\)
3. \( \frac{2}{3}\text{C}\)
4. \( \frac{5}{3}\text{C}\)
Surface charge density on the positive plate of a charged parallel plate capacitor is \(\sigma.\) Energy density in the electric field of the capacitor is:
1. \(\frac{\sigma^2}{\varepsilon_0}\)
2. \(\frac{\sigma^2}{2\varepsilon_0}\)
3. \(\frac{\sigma}{\varepsilon_0}\)
4. \(2\sigma^2 \varepsilon_0\)
Two capacitors of capacity \(2~\mu\text{F}\) and \(3~\mu\text{F}\) are charged to the same potential difference of \(6\) V. Now they are connected with opposite polarity as shown. After closing switches \(S_1~\text{and}~S_2\), their final potential difference becomes:
1. | \(\text{zero} \) | 2. | \(\frac{4}{3}~\text{V} \) |
3. | \(3~\text{V} \) | 4. | \(\frac{6}{5}~\text{V} \) |
1. | \(16\) | 2. | \(8\) |
3. | \(64\) | 4. | \(32\) |
A positive charge \(q\) and a negative charge \(-q\) are placed at \(x=-a\) and \(x=+a\) respectively. The variation of \(V\) along \(x\text-\)axis is represented by the graph:
1. | 2. | ||
3. | 4. |
Which of the following statements is correct regarding the electrostatics of conductors?
1. | The interior of the conductor with no cavity can have no excess charge in the static situation. |
2. | The electrostatic potential is constant throughout the volume of the conductor. |
3. | The electrostatic potential has the same value inside as that on its surface. |
4. | All of these. |