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 xx 10^(3) Nm2//C`. (a) What is the net charge inside the box? (b) If the net outward flux through the surface of the box were zero, could you conclude that there were no charges inside the box? Why or Why not?

Explanation

Using the concept of Gauss's theorem
Given net outward flux `f=("change")/e_0=q/e_0 implies q=e_0 f=8.854 times 10^-12 times 8 times 10^3`
From Gauss's theorem `q=0.07 times 10^-6 C=0.07 mu C` The flux is outward hence the charge is positive in nature.