Careful measurement of the electric field at the surface of a blackbox indicates that the net outward flux through the surface of thebox is 8.0 × 103 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? Whyor Why not?
a)
Given: Net outward flux through the surface of the box is 8 × 10 3 Nm 2 /C .
From Gausses law, the electric flux through the surface of the box is given as,
ϕ = q ε 0
Where, q is the net charge of the body, and ε 0 is the permittivity of the free space.
By substituting the values in the above equation, we get
8 × 10 3 = q 8.854 × 10 − 12 q = 70.832 × 10 − 9 C = 0.071 μC
Thus, the net charge inside the box is. 0.071 μC .
b)
Net flux depends upon the net charge contained in a body. If net flux is zero it means that the body may have net charge zero or the body may have equal amounts of negative and positive charges.
Thus, we cannot conclude that there were no charges inside the box.
a)
Given: Net outward flux through the surface of the box is
From Gausses law, the electric flux through the surface of the box is given as,
Where,
By substituting the values in the above equation, we get
Thus, the net charge inside the box is.
b)
Net flux depends upon the net charge contained in a body. If net flux is zero it means that the body may have net charge zero or the body may have equal amounts of negative and positive charges.
Thus, we cannot conclude that there were no charges inside the box.
