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. `(piq)/(6(4pi epsilon_(0)))`
B. `(q)/(6(4pi epsilon_(0)))`
C. `(2piq)/(6(4pi epsilon_(0)))`
D. `(4piq)/(6(4pi epsilon_(0)))`

Answer

d

Explanation

By Gauss law in electrostatic, electric flux through any closed surface is `(q)/(epsilon_(0))`
If the charge is located at the centre of the cube it is placed symmetrically with respect to each other. `:.` Electric flux through each face is
`(1)/(6) (q)/(epsilon)=(1)/(6) (4piq)/((4pi epsilon_(0)))`