Two concentric conducting spherical shells carry charge \(Q\) each. The inner shell is earthed. The charge that flows into the earth is:
1. | \(Q\) | 2. | \(\frac{3Q}{2}\) |
3. | \(\frac{-Q}{2}\) | 4. | \(\frac{-3Q}{2}\) |
The equivalent capacitance between the points \(A\) and \(B\) in the given network is:
1. \(25~\mu\text{F}\)
2. \(16~\mu\text{F}\)
3. \(21~\mu\text{F}\)
4. \(12~\mu\text{F}\)
Five equal capacitors connected in series have a resultant capacitance of \(4~\mu\text{F}\). The total energy stored in these when these are connected in parallel and charged to \(400\) V is:
1. \(1~\text{J}\)
2. \(8~\text{J}\)
3. \(16~\text{J}\)
4. \(4~\text{J}\)
Two identical parallel plate capacitors are placed in series and connected to a constant voltage source of \(V_0\) volt. If one of the capacitors is completely immersed in a liquid with dielectric constant \(K\), the potential difference between the plates of the other capacitor will change to:
1. \(\frac{K + 1}{K} V_{0}\)
2. \(\frac{K}{K + 1} V_{0}\)
3. \(\frac{K + 1}{2 K} V_{0}\)
4. \(\frac{2 K}{K + 1} V_{0}\)
A parallel plate air capacitor has a capacity of \(C\), the distance of separation between plates is \(d\) and potential difference \(V\) is applied between the plates. The force of attraction between the plates of the parallel plate air capacitor is:
1. \(\frac{C^{2} V^{2}}{2 d}\)
2. \(\frac{C V^{2}}{2 d}\)
3. \(\frac{C V^{2}}{d}\)
4. \(\frac{C^{2} V^{2}}{2 d^{2}}\)
1. | increases by a factor of \(4\). |
2. | decreases by a factor of \(2\). |
3. | remains the same. |
4. | increases by a factor of \(2\). |
In the given circuit if point \(C\) is connected to the earth and a potential of \(+2000~\text{V}\) is given to the point \(A\), the potential at \(B\) is:
1. | \(1500\) V | 2. | \(1000\) V |
3. | \(500\) V | 4. | \(400\) V |
The figure shows some of the equipotential surfaces. Magnitude and direction of the electric field is given by:
1. | \(200\) V/m, making an angle \(120^\circ\) with the \(x\text-\)axis |
2. | \(100\) V/m, pointing towards the negative \(x\text-\)axis |
3. | \(200\) V/m, making an angle \(60^\circ\) with the \(x\text-\)axis |
4. | \(100\) V/m, making an angle \(30^\circ\) with the \(x\text-\)axis |
When a negative charge is released and moves in the electric field, it moves towards a position of:
1. | lower electric potential and lower potential energy. |
2. | lower electric potential and higher potential energy. |
3. | higher electric potential and lower potential energy. |
4. | higher electric potential and higher potential energy. |
In the given figure if \(V = 4~\text{volt}\) each plate of the capacitor has a surface area of\(10^{-2}~\text{m}^2\) and the plates are \(0.1\times10^{-3}~\text{m}\)apart, then the number of excess electrons on the negative plate is: