# Flux through each face on a cube

#### Ed Aboud

1. Homework Statement

A point charge q is placed at one corner of a cube of edge a. What is the flux through each of the cube faces?

2. Homework Equations

3. The Attempt at a Solution

I drew a diagram of the situation. I'm pretty sure that I should use Gauss' Law and some symmetry arguments but I am not sure how to integrate over the cubes faces taking into account that the electric field produced by the point charge is radially outwards, like a sphere cutting through the face of the cube ( poorly described I know, sorry).

Thanks for the help.

Related Advanced Physics Homework Help News on Phys.org

#### VKint

By Gauss's Law, the flux through the whole cube is just $$6q/\epsilon_0$$. Now, apply a simple symmetry argument to get the answer.

#### Ed Aboud

I'm not sure why is it 6q ? If there is only one charge of magnitude 1q surely the flux is

$$q/\epsilon_0$$

#### Doc Al

Mentor
Right: The total flux from that charge is just q/ε0. So what's the total flux through the cube? Through each face of the cube? (No integration needed, just symmetry.)

#### FedEx

So...
What is the answer you are getting?

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving