A point charge q is kept at e distance x from the centre of a neutral metallic cube.

Options

A. Net electric field intensity at the centre is zero
B. Electric field intensity due to induced charges on cube at its centre is zero.
C. Electric field intensity due to point charge at the centre is non-zero.
D. Electric field intensity at the centre of cube due to point charge and induced charges on cube will be equal in magnitude.

Answer

A, C, D

Explanation

In electrostatic condition the net electric field intensity inside the metal is zero. Hence it is zero everywhere and of course the centre of the cube is also not excluded. So, option (a) is correct.
Everywhere including the centre, the net electric field intensity is zero due to cancellation of electric field intensity of point charge and induced charge on the cube. Hence, the electric field intensity due to induced charges only at the centre cannot be zero. So, option (b) is not correct (c) is correct.
For the net electric field intensity to become zero, the electric field of the point charge and induced charges must be equal in magnitude and opposite to each other in direction. Thus option (d) is correct.