# Flux of a cube

Electric Flux of a cube

## Homework Statement

A point charge of magnitude 9.10 nC is at the center of a cube with sides of length 0.685 m.

What is the electric flux through each of the six faces of the cube?

What would be the flux Phi_1 through a face of the cube if its sides were of length 0.250 m?

4*pi*Q

## The Attempt at a Solution

I tried 4*pi*9.10 which equals 411 and it says I'm off by an additive constant

I know to do part2, the flux must be found for part1 but i'm not sure if i'm applying gauss's law correctly, I know that you can use symmetry to solve these cube problems but I haven't had a decent example of this type of problem and we already have hw on it.

Last edited:

Doc Al
Mentor
Hint: What's the total flux through any closed surface that surrounds a charge Q? Once you find the total flux, then use symmetry to find the flux through each side of the cube.

Hint: What's the total flux through any closed surface that surrounds a charge Q? Once you find the total flux, then use symmetry to find the flux through each side of the cube.

Is the flux on any surface that surrounds a charge Q => Qenclosed / Eo

Last edited:
Doc Al
Mentor
Is the flux on any surface that surrounds a charge Q => Qenclosed / Eo
Yes it is.

Yes it is.

Though with this, knowledge, I'm still not sure how to figure out the flux on each side of the cube.

Doc Al
Mentor
Start by figuring out which side has the most flux passing through it.

hummm is it Q/Eo/6?