If the electric flux entering and leaving an enclosed surface respectively is `phi_1` and `phi_2`, the electric charge inside the surface will be

The electric flux through the surface

If the electric flux entering and leaving a closed surface are 6 xx 10^6 and 9 xx 10^6 SI units respectively, then the net charge inside the surface of permittivity of free space epsilon_0 is

The electric flux through the surface :

Electric flux through a closed surface in free space enclosing a charge q is