A point charge q is placed at the centre of a cube. What is the flux linked.
a with all the faces of the cube?
b. with each face of the cube?
c. if charge is not at the centre, then what will be the answer of parts a and b ?

Options

A. `(pi q)/(6 (4pi in_(0)))`
B. `(q)/(6 (4pi in_(0)))`
C. `(2pi q)/(6 (4pi in_(0)))`
D. `(4pi q)/(6 (4pi in_(0)))`

Answer

D

Explanation

According to Gauss's law in electrostaics the electric flux crossing any closed surface if `q//in_(0)`. If a charge `q` is located at the centre of a cube,then equal electric flux is threading each face of cube,Since a cube has six faces, so the electric flux through each face to cube
`= (1)/(6) ((q)/(in_(0))) = (1)/(6) ((4pi q))/((4pi in_(0)))`