The Motor Effect

Right-hand rule for current in wire

A current-carrying wire in a magnetic field will experience a force (as it produces its own magnetic field that interacts with the other).

F = BIL

Unit for B = Tesla

Force (N) = magnetic flux density (T) x current (A) x length (m)

Fleming’s Left hand rule gives you the direction of the force.

Practical for flux density:

1. Place magnet on balance.

2. Tare balance, measure ‘mass’ when known current flowing.

3. Convert to Newtons (e.g. 1N here).

4. Measure length of wire in a field.

5. Rearrange F=BIL to calculate B.