Magnetic Fields Due to Currents

The magnetic field produced by a straight wire is

where

The direction of the magnetic field is given by the Right Hand Rule.

A magnetic field is produce by a circular current loop,

The magnetic field at the center of a circular current loop is

The magnetic field inside a solenoid is

Force on a Current-Carrying Wire

Torque on a Current Loop

Return to Ch 20, Magnetism
(c) Doug Davis, 2003; all rights reserved