To keep a body moving in circular path, a force named ‘centripetal force’ acts towards the center of the path. This force acts along the radius and at right angle to the circular motion of body.

So, work done by body in going around the circular path is zero because displacement of body is perpendicular to the direction of centripetal force and by the formula:

Work= FS cos θ where θ=90°

And cos 90°= 0

So, work done = zero