Question

A Gaussian cube of side s is placed inside a uniformly charged insulating sphere of radius 2s and charge Q. What is the electric flux on the Gaussian cube?

a. 3Q/(32pi Eo)
b. 32Q/(3 pi Eo)
c.) 3Q/(32 Eo)
d.) 32Q/(3 Eo)
e. Zero

Answer 1

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/gaulaw.html
now u shud be able to find it

Answer 2

The answer is a) 3Q/(32pi Eo)
Solution:
Since the sphere is insulating the charge is distributed uniformly throughout the volume.
So the volume charge density= Q/volume of sphere = 3Q/4 pi (2s)^3
= 3Q/32 pi s^3.

The flux through the cube = Charge enclosed by cube/Eo .

Charge enclosed by cube = (volume charge density) * (volume of cube)
= ( 3Q/32 pi s^3 ) * s^3 = 3Q/32 pi .

=> Flux = ( 3Q/32 pi )/Eo = 3Q/(32pi Eo)