Question

Why must continuous mechanical work be supplied to an AC generator?

Options

• The generator must oppose a strong, steady field rather than a flux change.

• The induced EMF continuously accelerates the rotation without work.

• A rotating coil has no changing magnetic flux.

• As the coil rotates, the induced EMF opposes the rotation as back EMF.

Answer 1

Rotation of the coil induces an EMF that opposes the rotation, called back EMF. Mechanical work must be supplied continuously to maintain rotation.