The electric charges are distributed in a small volume. The flux of the electric field through a spherica surface of radius 10 cm surrounding the total charge is `20 V - m`. The flux over a concentric sphere of radius 20 cm will be

Options

A. 20 V-m
B. 25 V-m
C. 40 V-m
D. 200 V-m

Answer

A

Explanation

According to Gauss' theorem, electric flux is
`phi_(E)=oint_(s)E.dS=(1)/(epsilon_(0))(q)`
i.e. the flux linked with a closed body is independent of the shape and size of the surface. So, electric flux remain constant.
`"Hence, "phi_(E)=20" V-m"`