A point charge `+10muC` is at a distance 5 cm directly above the centre of a square of side 10 cm as show in the figure.
What is the magnitude of the electric flux through the square?

Explanation

Consider a charge q = 10 `mu C` be at a distance 5 cm from the square ABCD of side 10 cm [Fig. (ii)]. The square ABCD may be taken as one force a cube whose each side is 10 cm. Consider a cube of side 10 cm having given charge at its centre.
According to Gauss.s law total electric flux through all the six faces of cube, is
`phi = (q)/(epsilon_(0))`

`therefore` Flux from each face or from square ABCD will be
`phi_(E) = (1)/(6) xx (q)/(epsilon_(0)) = (10 xx 10^(-6))/(6xx8.85 xx 10^(-12)) Nm^(2) C^(-1)`
`= 0.1882 xx 10^(6)`
`1. 882 xx 10^(5) Nm^(2) C^(-1)`