A charge Q is uniformly distributed over a rod of length l. Consider a hypothetical cube of edge l with the centre of the cube at one end of the rod. Find the minimum possible flux of the electric field through the entire surface of the cube.

Explanation

Given length of the rod = edge of cube = l
Portion of rod inside the cube = l/2
Total charge = Q
Linear charge density = `(Q/ l (epsilon_0))` of rod
We know flux = charged enclosed in the
rod inside the cube ` = l/2 xx (Q / l(epsilon_0)) = (Q / 2(epsilon _0))` .