Electric Field due to a charged conducting sheet

[vodkasoup]

Homework Statement

A conducting sheet 10m x 10m x 1mm carries a charge of 1 mC. What is the electric field magnitude in kV m-1 just above the centre of the sheet?

Homework Equations

ρ=Q/Volume

E=ρ/2ε₀

The Attempt at a Solution

I have arrived at an answer by the following:

ρ = 1x10^-3C / 10m x 10m x 1mm = 0.01C/m³

E = 0.01 / 2 x 8.85x10^-12 = 565MV/m

However, the answer is given as 565kV/m, which I can only arrive at if I use 8.85x10^-9 as the free space permittivity. Where have I gone wrong?Many thanks.

 

[Doc Al]

ρ=Q/Volume

E=ρ/2ε₀

The density you need is the surface charge density, Q/Area (which is usually represented by σ). (Not the volume charge density ρ.)

 

[vodkasoup]

Ah. Whoops. Thank you very much!