The electric field due to a dipole at a distance $r$ on its axis is

Two charges of $+25 \times 10^{-9} \, C$ and $-25 \times 10^{-9} \, C$ are placed $6 \, m$ apart. Find the ratio of the electric field intensity at a point $4 \, m$ from the center of the electric dipole on the $(i)$ axial line and $(ii)$ equatorial line.

$A$ point particle of mass $M$ is attached to one end of a massless non-conducting rod of length $L$. Another point particle of the same mass is attached to the other end of the rod. The two particles carry charges $+q$ and $-q$ respectively. This arrangement is placed in a region of uniform electric field $E$. When the rod makes a small angle $(< 5^o)$ with the direction of the field,what is the minimum time required for the rod to become parallel to the field?

When is the torque on an electric dipole in an electric field maximum?

For an electric dipole with charge $q = 2 \times 10^{-6} \ C$ and separation distance $d = 0.01 \ m$,if the external electric field is $E = 5 \times 10^{5} \ N/C$,calculate the maximum torque acting on the dipole.

When does the torque acting on an electric dipole in a uniform electric field become zero?