Physics · Circular Motion & Momentum

As the object moves around in a circular track, its perpendicular distance from the center remains unchanged, so we can say that there is zero change in displacement. However, during circular motion object does cover distance in a circular path, so the change in distance is non-zero.In oscillations, linear motion, and random motion there is a change in perpendicular distance from the origin point so displacement is non-zero that is why A, C, and D are incorrect. 

In linear motion distance is equal to displacement and is non zero.

In circular motion, displacement is zero while distance is non zero.

In random motion displacement and distance are non zero.

In oscillations, displacement and but distance aee non zero.