The inward and outward electric flux for a closed surface unit of `N-m^(2)//C` are respectively `8xx10^(3)` and `4xx10^(3)`. Then the total charge inside the surface is [where `epsilon_(0)=` permittivity constant]

Options

A. `(-4xx10^(3))/(epsilon_(0))C`
B. `-4xx10^(3)epsilon_(0)C`
C. `-4xx10^(3)C`
D. `(12xx10^(3))/(epsilon_(0))C`

Answer

B

Explanation

Net flux from the surface
`phi_(2)-phi_(1)=q/(epsilon_(0))`
`:.q=epsilon_(0)(phi_(2)-phi_(1))`
`=epsilon_(0)(4xx10^(3)-8xx10^(3))`
`-4xx10^(3) epsilon_(0)C`