Name one device whose working depends on the force exerted on a current-carrying coil placed in a magnetic field.

A current-carrying conductor is placed perpendicularly in a magnetic field. Name the rule which can be used to find the direction of force acting on the conductor.

State two ways to increase the force on a current-carrying conductor in a magnetic field.

State Fleming's left-hand rule. Explain it with the help of labelled diagrams.

What is the principle of an electric motor? Name some of the devices in which electric motors are used.