A point charge +q is kept at a distance d/2 directly above the centre of a square surface of side d. Find the electric flux through the square.

Question

G1 Physics · Accepted Answer

Imagine the square as one face of a cube of side d. Because the charge is at distance d/2 from the square, it lies at the centre of that cube. By symmetry, the total flux q/ε₀ is equally shared by the six faces. Hence flux through the given square is q/(6ε₀). Correct answer: D.