Back emf (electromotive force)

The video tutorial explains the workings of electric motors, focusing on the concept of magnetic flux and induced EMF. It discusses how the magnetic flux changes as a current-carrying loop rotates in a magnetic field, leading to an induced EMF that opposes the change. The concept of back EMF is introduced, explaining how it affects the current in electric motors and its practical implications, such as dimming lights when motors start. The tutorial also covers the design of motors to maintain constant back EMF using multiple loops and a split ring commutator.

What happens to the magnetic flux through a current-carrying loop as it rotates in a magnetic field?

Explain the concept of back EMF in electric motors.

Why is the back EMF not present when the electric motor is not rotating?

How does the current through an electric motor change when it is starting up compared to when it is running at a constant speed?

What effect does starting an electric motor have on the lights in the same circuit?

What happens to the back EMF when an electric motor suddenly stops rotating?

Describe the role of the split ring commutator in a direct current electric motor.