The magnetic fields of a current-carrying wire and a nearby permanent magnet will interact and the wire and magnet exert a force on each other.
This is called the 'motor effect'.
If the current-carrying wire is placed at right angles to the magnetic field lines, the force will be at right angles to both the current direction and the lines of force of the field.
The direction of the force can be inferred using Fleming's left-hand rule.
The size of the force is proportional to the length of wire in the field, the current and the strength of the field.
The motor effect can result in a turning force on a rectangular current-carrying coil placed in a uniform magnetic field; this is the principle behind all electric motors.
The invention and development of practical electric motors have made an impact on almost every aspect of daily life |
1. Describe the interaction forces between a magnet and a
current-carrying conductor to include ideas about magnetic
fields
In your practical lessons you will:
 Investigate the motor
effect for a single wire
in a magnetic field and
apply the principles to
build a simple electric
motor.
Build a simple electric
motor and explain how
it works.
You should be able to:
Describe and explain
examples of uses of
electric motors that
have made significant
improvements to
people's lives.
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