$A$ given charge is situated at a certain distance from an electric dipole in the end-on position experiences a force $F$. If the distance of the charge is doubled,the force acting on the charge will be:

An electric dipole of length $3 \text{ cm}$ is placed with its axis making an angle of $60^\circ$ with a uniform electric field of $5 \times 10^4 \text{ N/C}$. It experiences a torque of $9\sqrt{3} \text{ Nm}$. The magnitude of charge on the dipole is $(\sin 60^\circ = \frac{\sqrt{3}}{2})$

Two charges of $-4 \ \mu C$ and $+4 \ \mu C$ are placed at the points $A(1, 0, 4) \ m$ and $B(2, -1, 5) \ m$ located in an electric field $\vec{E} = 0.20 \ \hat{i} \ V/cm$. The magnitude of the torque acting on the dipole is $8 \sqrt{\alpha} \times 10^{-5} \ Nm$. Where $\alpha = $ . . . . . .

Choose the incorrect statement from the following.

An electric dipole is formed by placing a charge of $4 \times 10^{-8} \ C$ at a distance of $2 \times 10^{-2} \ cm$. If it is placed in an electric field of $4 \times 10^8 \ N/C$,what is the maximum torque acting on it and the work done to rotate the dipole by $180^{\circ}$?

In the situation shown in the diagram,if $q \ll |Q|$ and $r \gg a$,find the net force on the free charge $-q$ and the net torque on it about $O$ at the instant shown. ($p = 2aQ$ is the dipole moment).