The figure shows an imaginary cube of length `L//2` and a uniformly charged rod of length `L` touching the centre of the centre of the right face of the cube normally.At time `t=0` the rod starts moving to the left slowly at a constant speed `v` .The electric flux `(F)` thriguh the cube si plotted against time `(t)` .The correct graph showing the variation of flux with time is

Options

A.
B.
C.
D.

Answer

C

Explanation

Flux first increase linearly (:.v is constant remains cosntant (when length `L//2` is inside the cube) and then decrease linearly (as rod moves out)