Finding an electric field on a disk using surface charge density

Thread starter gretchin
Start date Jan 29, 2012
Tags

Charge Charge density Density Disk Electric Electric field Field Surface Surface charge density

AI Thread Summary

To find the electric field produced by a charged disk at a point on its central axis, the surface charge density and the distance from the disk are crucial. The formula for the electric field involves integrating the contributions from elementary rings of charge across the disk's surface. The specific values given include a disk radius of 2.30 cm, a surface charge density of 5.22 μC/m², and a distance of 11.2 cm from the disk. The integration process utilizes the formula: (int)dEz = sigma/2ep0 (1-z/sqrt(z^2+r^2)). This approach allows for calculating the electric field's magnitude at the specified point along the axis.

Jan 29, 2012

gretchin

Homework Statement

A disk of radius 2.30 cm has a surface charge density of 5.22 μC/m2 on its upper face. What is the magnitude of the electric field produced by the disk at a point on its central axis at distance z = 11.2 cm from the disk?

Homework Equations

Formula for an electric field

The Attempt at a Solution

(int)dEz= sigma/2ep0 (1-z/sqrt(z^2+r^2)

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Jan 29, 2012

pabloenigma

Break up the disk into elementary rings and integrate.

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