Careful measurement of the electric field at the surface of a black box indicates that the net outward flux through the surface of the box is `8.0 xx10^(3) Nm^(2)`/C. What is the net charge inside the box?

Explanation

Given, `phi=8.0xx10^(3) N-m^(2)//C`
`epsi_(0) =8.854xx10^(-12) C^(2)-N^(-1) -m^(-2)`
Net flux `phi=("Charge (q)")/epsi_(0)`
`implies q=phi epsi_(0)=8xx10^(3)xx8.854xx10^(-12)`
`:. q=0.07 muC`
The flux is outward hence the charge is positive in nature.