A positive charge (+q) is located at the centre of a circle as shown in figure. $W_1$ is the work done in taking a unit positive charge from A to B and $W_2$ is the work done in taking the same charge from A to C. Then.

$W_1 = W_2 = 0$

Point A, B and C are at the same distance from charge +q; hence electrical potential is the same at these points, i.e.  There is no potential difference between A, B and C. Hence W₁ = W₂ = 0.