Question

A cube of side “a” is placed in an electric field directed along the positive X -axis. The net number of flux lines passing through the cube is 

(i) 6a² E₀ 

(ii) 2a² E₀ 

(iii) 4a² E₀ 

(iv) Zero

Answer 1

Correct option is : (iv) Zero

The cube is placed such that the electric field is parallel to one of the edges along the positive X axis. The number of lines of force entering the face perpendicular to the edge is equal to the number of lines of force leaving.