Segments in this Video

Motors and Magnets (01:45)


Electric motors usually convert 80% of electrical energy into mechanical energy. In contrast, gasoline engines are only 30% efficient. Electric motors require a movable current-carrying coil and one or more fixed magnets.

Motors: Current and Magnet Interaction (02:16)

Electric current exerts a force on magnets, the compass needle for example. The interactive force between a magnet and an electric current is the foundation of an electric motor.

Electric Motors: Left Hand Rule (02:28)

When a current-carrying wire is placed near a magnet, the magnetic field created by the current will interact with the field of the magnet. The left hand rule shows the direction of the thrust on a conductor carrying a current in a magnetic field.

Electric Motors: Motor Force (02:58)

When a conducting wire is placed between a pair of separate magnets, the motor force extends at right angles to both current and magnetic field. The equation F = kB1IL is explained. Scientists measure the strength of the magnetic field in teslas.

Electric Motors: Motor Torque (02:18)

When a coil of current-carrying wire is placed in a magnetic field, the motor force may behave differently than with a straight wire.

Electric Motors: DC Motors (05:25)

A direct current (DC) motor consists of a magnet (or magnets) fixed in a housing to produce a magnetic field. The key component of the DC motor is the split ring commutator that is insulated from the motor shaft.

For additional digital leasing and purchase options contact a media consultant at 800-257-5126
(press option 3) or

Electric Motors

Part of the Series : Electricity: A 3-D Animated Demonstration
DVD (Chaptered) Price: $99.95
DVD + 3-Year Streaming Price: $149.93
3-Year Streaming Price: $99.95



This program explores the basic principles behind the operation of AC and DC motors. An explanation is given about how one or more fixed magnets, either permanent or electromagnetic, can cause linear movement or rotation of a current-carrying wire. A hand rule is developed to predict motor force. Motor torque is explained as a prelude to the practical design of a direct current motor. Specific modules include Motors and Magnets, Current and Magnet Interaction, Left-Hand Rule, Motor Force, Motor Torque, and DC Motors. Correlates to all National CTE Organizational Standards (including the provisions of the Perkins Act). A viewable/printable instructor’s guide is available online. A Shopware Production. (18 minutes)

Length: 18 minutes

Item#: FMK38729

ISBN: 978-1-4213-8976-9

Copyright date: ©2008

Closed Captioned

Related Resources

Performance Rights

Prices include public performance rights.