Two tiny spheres carrying charges `1.5 muC` and `2.5 muC` are located 30 cm apart. Find the potential
(a) at the mid-point of the line joining the two charges and
(b). At a point 10 cm from this mid-point in a plane normal to the line and passing through the mid-point.

Explanation

(a) `2.4 xx 10^(5) V, 4.0 xx 10^(5) Vm^(-1)`, from charge 2.5 `muC` to `1.5 muC`.
(b) `2.0 xx 10^(5) V, 6.6 xx 10^(5) Vm^(-1)` in the direction that makes an angle. Of about `69^(@)` to the line joining charge 2.5 `muC` to `1.5 muC`