Two spheres $A$ and $B$ of radii 4 cm and 6 cm are given charges of $80 \mu \mathrm{C}$ and $40 \mu \mathrm{C}$ respectively. If they are connected by a fine wire, the amount of charge flowing from one to the other is

The angle between the electric dipole moment of a dipole and the electric field strength due to it on the equatorial line is

Two particles of equal mass $m$ and equal charge $q$ are separated by a distance of 16 cm . They do not experience any force. The value of $\frac{q}{m}$ is (if $G$ is the universal gravitational constant and $g$ is the acceleration due to gravity)

In the following diagram, the work done in moving a point charge from point $P$ to points $A, B$ and $C$ are $W_A, W_B$ and $W_C$ respectively. Then ( $A, B, C$ are points on semi-circle and point charge $q$ is at the centre of semi-circle)