# Probelm in electrostatiics

1. Oct 19, 2004

### nibal

Hello guys,
I have a problem with actually starting up this problem (2.6) in "Intrroduction to electrodynamics" Griffiths.

Question

Find the electric field a distance z above the center of a flat cricular disk of radius R, which carries a uniform surface charge (sigma)?

I am having problems setting it up especially how 'da' looks like and also the whole integral.

Thanks.

2. Oct 19, 2004

### Tide

Find the electric field produced by an element of charge $\sigma \rho d\rho d\theta$ at a position along the z-axis. You only need to consider the z-component of field due to the symmetry. Then it's just a matter of integration.

Last edited: Oct 19, 2004
3. Oct 22, 2004

### nibal

Thank you i get it now Tide.