Homework Help: Another charge density

1. Nov 24, 2004

mborn

At two different points of an irregularly shaped conductor, the field had the following two values
5.6*10^4 and 2.8*10^4 respectively. Find the local surface charge density at;
1- the point with the greatest radius of curvature,
2- the point with the smallest raduis of curvature.

I know that at the point with the smallest radius of curvature, charges tend to accumulate, meaning that the first field corresponds to the point of the smallest radius of curvatire and I used E = sigma/epsilon_naught to find the two local charge densities. The answers I have is the reverse of what I got, He gave he one I had for the smallest r as the one of the greatest r! Is there anything wrong here, me or him?

M B

2. Nov 24, 2004

Tide

Are you sure charge will accumulate where the radius of curvature is smallest? :-)

3. Nov 25, 2004

mborn

that is what is said on my book?

Charges tend to accumulate at the points at which radius of curvature is the smallest, that is at sharp points.

M B

Last edited: Nov 25, 2004
4. Nov 25, 2004

Tide

If like charges repel why would they want to crowd together in tight places when they can spread out over regions of lower curvature?