Quiz8-2007-102

# Quiz8-2007-102 - center of the sphere. Outsite the sphere,...

This preview shows pages 1–2. Sign up to view the full content.

a) What is the surface charge density on the surface of the sphere. 2 4 R Q Area Q π σ = = b) Find and plot the magnitude of the electric field E inside and outside the sphere. The sphere is a conductor therefore electric field inside is zero: 0 = inside E , r < R Outside the sphere, there is an electric field due to the charge enclosed by the surface: 2 2 4 4 r Q E Q r E A d E Q A d E πε ε = = = = r r r r r For r > R, E decreases as r goes to infinity. c) Find and plot the potential V , inside and outside the sphere. = = r d E V V V i f r r Let , a reference potential at the initial point. Then for E=0, r < R, we have 0 V V i = () () () 0 0 0 0 V r V r d V r V V r V V f = = = = = r This holds for r < R as well as for r = R. Up to now we see that there is a constant potential inside the sphere, and this potential is same as the reference potential at the

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: center of the sphere. Outsite the sphere, r > R, we have calculated that 2 4 r Q E πε = r and we know that ∫ ∫ − = ⋅ − = − = ∆ r R i f dr r Q r d E V V V 2 4 r r ( ) ( ) ( ) ( ) ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ − ⋅ + = ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ + − ⋅ − = ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ − ⋅ − = − = − = ∆ ∫ R r Q R V r V R r Q r Q dr r Q R V r V V r R r R 1 1 4 1 1 4 1 4 1 4 2 Right when r = R, we have ( ) ( ) R V r V = ; for r > R potential starts to decrease, approaching zero as r goes to infinity....
View Full Document

## This note was uploaded on 04/23/2010 for the course -- -- taught by Professor -- during the Spring '10 term at Bilkent University.

### Page1 / 2

Quiz8-2007-102 - center of the sphere. Outsite the sphere,...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online