What is meant by motor effect? or define motor effect.

When the current flows through a wire is placed in the magnetic field, a movement is developed in the wire. This phenomenon is called motor effect. 

A current-carrying wire or coil can exert a force on a permanent magnet. This is called the motor effect. The wire could also exert a force on another nearby current-carrying wire or coil. The force increases if the strength of the magnetic field and/or current increases.

It is used to predict in which direction a current-carrying wire will move in a magnetic field so make sure that you revise it well. If the two ends of the wire used to make the coil were connected directly to the electricity supply, they would soon twist together, preventing the coil from turning. The angle formed between the wire and the direction of the magnetic field. (θ) The length of the wire, carrying the current, in the magnetic field.

Electric motors are found in many household devices e.g. tumble dryers, washing machines, vacuum cleaners, electric knives, food mixers, hair dryers and electric toothbrushes. A coil of wire carrying a current in a magnetic field experiences a force that tends to make it rotate.Electric motors are found in industrial fans, blowers and pumps, machine tools, household appliances, power tools and disk drives. Small motors may be found in electric watches.

Inside an electric motor, permanent magnets are set onto a ring surrounding a coil of wire. When the appliance's switch is flicked on, electrons flow through the wire, turning it into an electromagnet. The attractive and repulsive forces of the permanent magnets around it make the electromagnet spin.