When a coil of wire carries an electric current in a magnetic field, it experiences a force that can cause the coil to rotate. This is how electric motors function.

Key Points

• We use a coil of wire that is free to rotate between two opposite magnetic poles.
• Each end of the coil is connected to a split-ring commutator. Each side of the commutator is connected to the opposite poles of a direct current (DC) power supply.

How the DC Electric Motor Works 1. The flowing current will create a magnetic field around the coil.

2. The magnetic field produced by the current will interact with the magnetic field produced by the permanent magnets.

3. As a result, a force is exerted on the coil.

In the case of the diagram, the magnetic field exerts an upward force on the left side and a downward force on the right side. This leads to a clockwise rotation of the coil.

At this point, there are upward and downward forces acting on the coil

The split ring commutator provides a point of contact between the coils and the external circuit. Carbon brushes, mounted on either side of the commutator, connect the rotating and stationary parts of the motor. This ensures that the coil does not tangle.