Ask a Teacher

A point charge +10 mue C is a distance 5 cm directly above the centre of a square of side 10 cm.What is the magnitude of the electric flux through the square?

The square can be considered as one face of a cube of edge 10cm with a centre where charge q is placed. According to Gauss's theorem for a cube, total electric flux is through all its six faces.

Hence, electric flux through one face of the cube that is, through the square,

where         ?_o = permittivily of free space
                       = 8.854 × 10^-12 N^-1C²m^-2
                    q = 10 ?c
                       = 10 × 10^-6 C
                   

                       = 1.88 ×10⁵N m²C^-1

Therefore, electric flux through the square is
           1.88 ×10⁵N m²C^-1