Question

when displacement is zero??

Answer 1

when any object travell some amount of journy and return back to same place then desplacement said to be zero

Answer 2

hey there here is your answer

displacement will be zero if an object moves from one point and come back to the same. After covering some distance.

let us take an example
a body moves from a point A to a point t B and come back to its initial position i.e to the point A then the displacement is zero