A point charge Q is at distance a/2 above a square plate of side a as shown. The electric flux through the shaded region is NQ/(48ε₀). Find N.

Question

G1 Physics · Accepted Answer

Using symmetry as in the source figure, the shaded region receives contributions equivalent to three quarter portions and a half factor: Φ=[Q/(6ε₀)](1/4+1/4+1/4)(1/2)=5Q/(48ε₀) according to the source construction. Hence N=5.