Physics Demo Number: 207
Approximate Run Time: 5 min
World's Simplest Motor
Demo Description
A simple homopolar motor built out of a D-Cell battery, magnet, metal leads and coil of wire. The wire coil is placed in the field of the magnet.
The enamel on the part of
the wire in touch with the leads is partially scraped, so that the wire
conducts electricity in only one orientation of the coil and not the
other.
If given a slight push, the
coil begins to rotate.
Scientific Principles
A current-carrying loop in a magnetic field experiences a torque. This can be utilized to create a motor.Equipment
- The battery, magnet and leads are already assembled.
- Wire coil
Equipment Location
Kit 162 on [B-1-3] (Same kit as Demo 162)
Instructions
The first two
pictures show how the magnet and D-cell battery are housed. This does
not need to be changed.
The third photo shows the motor in action.
To start the motor, simply place the wire on top of the leads as shown. A gentle nudge might be necessary to get it spinning.
PLEASE treat the wire loop with care and do not to distort it - it took hours to get it to a shape which spins smoothly!