The inward annd outward electric flux from a closed surface are respectively `8xx10^(3) and 4xx10^(3)` units. Then the net charge inside the closed surface is

Options

A. `epsilon_(0) xx 10^(6)`
B. `- epsilon_(0) xx 10 ^(6)`
C. `- 2 epsilon_(0) xx 10^(6)`
D. `3 epsilon_(0) xx 10^(6)`

Answer

D

Explanation

By Gauss law, we know that
`phi = (q)/( epsilon_(0)) ` Here, Net electric flux , `phi = phi_(2) - phi_(1)`
` 9 xx 10^(6) - 6 xx 10^(6) = (q)/( epsilon_(0)) rArr q = 3 xx 10^(6) xx epsilon_(0)`