# Magnetic Field at the center of a sphere magnet

hansbahia

## Homework Statement

A sphere magnet of radius a has permanent uniform magnetization, z-axis. So we were trying to find the magnetic field at the center of the magnet in class.

## Homework Equations

$j_M(θ)=Msin(θ)$

$dI=j_M(θ)adθ$

circular loop

$r_{loop}=asin(θ)$

## The Attempt at a Solution

When using Biot-Savart equation for magnetic field of a ring why do you use*
$R^3=(a^2+z^2)$

$R^3=(r_{loop}^2+z^2)$

for the denominator????

Last edited:

Homework Helper
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When using Biot-Savart equation for magnetic field of a ring why do you use*
$R^3=(a^2+z^2)$

$R^3=(r_{loop}^2+z^2)$