Question

A point charge of −3μC is locatedat the center of a sphere with a radius r=5cm. What is the net electric flux through the surface?

Answer 1

IE = E x A

Where:

IE = electric flux

A = surface area = 4 pi r^2 = 4 pi (5)^2 = 314.16 cm^2

E =electric field = kq /R^2

q = charge = - 3uC

k = 1/4pi ∈0

∈0 = permittivity of free space= 8.85 x10^-12

IE =kq /R^2 * 4 pi r^2

IE = kq * 4 pi

IE = 1/4pi ∈0 * q * 4´pi

IE = q / ∈0

IE = -3uC / 8.85 x10^-12 = -3x10^-6 C / 8.85 x10^-12 = -0.33898305 x 10 ^6 Nm^2 /C

• The net electric flux through the surface is ,-0.33898305 x 10 ^6 Nm^2 /C