Electric field at the equator of a dipole is $E$. If both dipole moment and distance are doubled,then the electric field will be $:-$

Two point charges $-q$ and $+q$ are placed at a distance of $L$,as shown in the figure. The magnitude of electric field intensity at a distance $R$ $(R \gg L)$ varies as:

An electric dipole is placed along the $x$-axis with its center at the origin. The line $OP$ makes an angle of $\frac{\pi}{3}$ with the $x$-axis. If the electric field at point $P$ makes an angle $\theta$ with the $x$-axis,then $\theta$ is equal to:

Two opposite charges each of magnitude $500 \mu C$ are $10 \ cm$ apart. Find the electric field intensity at a distance of $25 \ cm$ from the midpoint on the axial line of the dipole.

When a test charge is brought in from infinity along the perpendicular bisector of an electric dipole,the work done is ..........

Two small spherical balls of mass $10 \ g$ each with charges $-2 \ \mu C$ and $2 \ \mu C$,are attached to two ends of a very light rigid rod of length $20 \ cm$. The arrangement is now placed near an infinite nonconducting charge sheet with a uniform charge density of $100 \ \mu C / m^2$ such that the length of the rod makes an angle of $30^{\circ}$ with the electric field generated by the charge sheet. The net torque acting on the rod is (Take $\varepsilon_0 = 8.85 \times 10^{-12} \ C^2 / Nm^2$) (in $Nm$)