# Magnetism: The Motor Effect

## The Motor Effect

• The motor effect refers to the phenomena that a motor experiences a force when an electric current carries it through a magnetic field.

• It is caused by the interaction between the magnetic field and the electric current.

• The size of the force that acts on the conductor is directly proportional to the strength of the magnetic field and the amount of current flowing through the conductor.

• The direction of the force is at right angles to the direction of the current and the magnetic field.

• The direction of the force can be determined using Fleming’s left-hand rule. The thumb represents the motion (force), the first finger represents the field, and the second finger represents the current.

## Applying the Motor Effect

• Electric motors use the motor effect to spin a coil of wire inside the magnetic field.

• An electric motor works by causing a coil of wire to spin inside a magnetic field. The coil, also called an armature, is an electromagnet.

• When the current flows through the coil, the force on each side of the coil causes it to spin.

• The direction of motion of the coil can be reversed by either reversing the current or the magnetic field.

• In order to ensure that the coil continues to spin in the same direction, electric motors are fitted with a split-ring commutator, which allows the current to change direction every half turn.

## Practical Applications of the Motor Effect

• The motor effect is put into practical use in a variety of electrical appliances we use in everyday life such as washing machines, fans, and mixers.

• It is also used in industries to operate tools and machinery, and in transport systems like electric cars, metros and trams.

• Electric generators work based on the motor effect. But unlike motors, which convert electrical energy into mechanical energy, generators convert mechanical energy into electrical energy.

• Electric generators involve a coil of wire spinning within a magnetic field, causing a voltage to be induced across the ends of the wire, generating electricity.