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:
1. | \(KC \over 2(K+1)\) | 2. | \(2KC \over K+1\) |
3. | \(5KC \over 4K+1\) | 4. | \(4KC \over 3K+1\) |
An air capacitor of capacity \(C= 10~\mu\text{F}\) is connected to a constant voltage battery of \(12\) V. Now the space between the plates is filled with a liquid of dielectric constant \(5\). The charge that flows now from battery to the capacitor is:
1. \(120~\mu\text{C}\)
2. \(699~\mu\text{C}\)
3. \(480~\mu\text{C}\)
4. \(24~\mu\text{C}\)
Four equal charges \(Q\) are placed at the four corners of a square of each side \(a\). Work done in removing a charge \(-Q\) from its centre to infinity is:
1. \(0\)
2. \(\frac{\sqrt{2} Q^{2}}{4 \pi \varepsilon_{0} a}\)
3. \(\frac{\sqrt{2} Q^{2}}{\pi \varepsilon_{0} a}\)
4. \(\frac{Q^{2}}{2 \pi \varepsilon_{0} a}\)
1. | \(V={p\cos \theta \over 4 \pi \varepsilon_0r^2}\) | 2. | \(V={p\cos \theta \over 4 \pi \varepsilon_0r}\) |
3. | \(V={p\sin \theta \over 4 \pi \varepsilon_0r}\) | 4. | \(V={p\cos \theta \over 2 \pi \varepsilon_0r^2}\) |
How much kinetic energy will be gained by an \(\alpha\text-\text{particle}\) in going from a point at \(70~\text{V}\) to another point at \(50~\text{V}\)?
1. | \(40~\text{eV}\) | 2. | \(40~\text{keV}\) |
3. | \(40~\text{MeV}\) | 4. | 0 |
A parallel plate condenser has a capacitance \(50~\mu\text{F}\) in air and \(110~\mu\text{F}\) when immersed in an oil. The dielectric constant \(k\) of the oil is:
1. \(0.45\)
2. \(0.55\)
3. \(1.10\)
4. \(2.20\)
Two thin dielectric slabs of dielectric constants \(K_1~\text{and}~K_2(K_{1} < K_{2})\) are inserted between plates of a parallel capacitor, as shown in the figure. The variation of electric field \(E\) between the plates with distance \(d\) as measured from plate \(P\) is correctly shown by:
1. | ![]() |
2. | ![]() |
3. | ![]() |
4. | ![]() |