Physics for IGCSE & O level - Magnets And Currents (Section 3 - No. 40)
What is the main purpose of a magnetic field in an electric motor?
To store energy.
To induce an e.m.f.
To provide the force that causes rotation.
To provide insulation.
Forklaring
The interaction of the current in the coil and the magnetic field creates the force (torque) that causes the motor's rotation.