Two charges \(\pm10\) µC are placed \(5.0\) mm apart. The electric field at a point P on the axis of the dipole \(15\) cm away from its centre O on the side of the positive charge, as shown in the figure is:
2.
1. | \(\frac{1}{\mathrm{R}^{6}}\) | 2. | \(\frac{1}{\mathrm{R}^{2}}\) |
3. | \(\frac{1}{\mathrm{R}^{3}}\) | 4. | \(\frac{1}{\mathrm{R}^{4}}\) |
An electric dipole is placed in a uniform electric field. The net electric force on the dipole,
1. | is always zero. |
2. | depends on the orientation of the dipole. |
3. | can never be zero. |
4. | depends on the strength of the dipole. |
An electric dipole is placed at an angle of \(30^\circ\) with an electric field intensity \(2\times10^5~ \mathrm{N/C}\). It experiences a torque equal to \(4 ~\mathrm{Nm}\). The charge on the dipole, if the dipole length is \(2~ \mathrm{cm}\), is:
1. | \(8~\mathrm{mC}\) | 2. | \(2~\mathrm{mC}\) |
3. | \(5~\mathrm{mC}\) | 4. | \(7~\mu \mathrm{C}\) |