question_answer

A point charge of 2 C is placed at centre of Faraday cage in the shape of cube with surface of 9 cm edge. The number of electric field lines passing through the cube normally will be :

A) \[1.9\ \times \ 1{{0}^{5}}\ N{{m}^{2}}/C\] entering the surface.

B) \[1.9\ \times \ 1{{0}^{5}}\ N{{m}^{2}}/C\] leaving the surface.

C) \[2.0\ \times \ 1{{0}^{5}}\ N{{m}^{2}}/C\] leaving the surface.

D) \[2.0\ \times \ 1{{0}^{5}}\ N{{m}^{2}}/C\] entering the surface.

Correct Answer: D

Solution :

Option is [d] correct

Explanation: The number of electric field lines passing through the cube normally and leaving the surface = \[\operatorname{Q}/{{\varepsilon }_{0}}\]