The electric field in a certain region is acting radially outward and is given by \(E=Aa.\) A charge contained in a sphere of radius \(a\) centered at the origin of the field will be given by:
| 1. | \(4 \pi \varepsilon_{{o}} {A}{a}^2\) | 2. | \(\varepsilon_{{o}} {A} {a}^2\) |
| 3. | \(4 \pi \varepsilon_{{o}} {A} {a}^3\) | 4. | \(\varepsilon_{{o}} {A}{a}^3\) |
If a charge \(Q\) is situated at the corner of a cube, the electric flux passing through all six faces of the cube is:
| 1. | \(\frac{Q}{6\varepsilon_0}\) | 2. | \(\frac{Q}{8\varepsilon_0}\) |
| 3. | \(\frac{Q}{\varepsilon_0}\) | 4. | \(\frac{Q}{2\varepsilon_0}\) |
| Assertion (A): | Point charges \(q_{1}\) and \(q_{2}\) produce electric field of magnitude \(E_{1}\) and \(E_{2}\) at a point and potential \(V_{1}\) and \(V_{2}\) at the same point. The electric field due to both the charges at that point must be \(E_{1}+E_{2}.\) |
| Reason (R): | The electric potential at that point due to both the charges must be \(V_{1}+V_{2}.\) |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
A short electric dipole has a dipole moment of \(16 \times 10^{-9} ~\text{C-}\text{m}. \) The electric potential due to the dipole at a point at a distance of \(0.6~\text{m}\) from the centre of the dipole situated on a line making an angle of \(60^{\circ}\) with the dipole axis is:
\(\left( \dfrac{1}{4\pi \varepsilon_0}= 9\times 10^{9}~\text{N-m}^2/\text{C}^2 \right) \)
| 1. | \(200~\text{V}\) | 2. | \(400~\text{V}\) |
| 3. | zero | 4. | \(50~\text{V}\) |
| 1. | \(\dfrac{r}{\sqrt[3]{2}}\) | 2. | \(\dfrac{r}{\sqrt[2]{2}}\) |
| 3. | \(\dfrac{2r}{3}\) | 4. | none of the above |
A point charge is brought in an electric field. The electric field at a nearby point,
| (a) | will increase if the charge is positive |
| (b) | will decrease if the charge is negative |
| (c) | may increase if the charge is positive |
| (d) | may decrease if the charge is negative |
| 1. | (a) only | 2. | (b), (c) |
| 3. | (c), (d) | 4. | (a), (d) |
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. | \(\frac{-3Q}{2}\) |
Given below are two statements:
Assertion (A): An isolated system consists of two particles of equal masses \(m=10\) gm and charges \(q_1=1~\mu \)C and \(q_2=-1~\mu \)C as shown in the figure. The initial separation of both charges is \(l=1\) m. Both the charges are given initial velocities \(v_1=1\) ms-1 and \(v_2=2\) ms-1 towards the right. The maximum separation between the charges is infinite.
Reason (R): The total energy (Kinetic energy + electrostatic potential energy) of the given two-particle system is positive and the initial velocity of separation is positive.
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |