Electromagnetism

 A moving charge creates a magnetic field  Electric current (I) is moving electrons, so a current-carrying wire creates a magnetic field  Right-Hand-Rule #1  If you point your thumb in the direction of the electric current, the direction your fingers curve is the direction of the magnetic field

Electromagnetic Induction  Faraday’s Law  When the strength of a magnetic field through a loop of conductive wire changes, an electric current is induced in the wire  The induced current produces it’s own magnetic field

Electromagnetic Induction  Lenz’s Law  An induced electric current always flows in a direction to oppose the change in magnetic field  The amount of magnetic field inside a loop wants to remain constant  Right-Hand-Rule #2  Loop your fingers in the direction of the induced current, and your thumb points in the direction of the induced magnetic field

Electric Motors  All electric motors are electromagnetic motors  Electric motors convert electrical energy into mechanical energy  Magnets within the motor interact with electric current to produce a force (and a torque)  F = I L × B  Electricity and magnetism are used to spin a coil, which does mechanical work

Electric Generators  Electric generators convert mechanical energy into electrical energy  A conductive coil or loop is physically rotated through a magnetic field. The changing magnetic field inside the loop induces a current through the loop.  Mechanical work and magnetism are used to create electricity