What is a key design feature of AC induction motors described in the source?

• A. Presence of carbon brushes
• B. Use of a commutator
• C. Absence of brushes and armature
• D. External rotor

Answer: (C)

AC induction motors are designed to operate without brushes or an armature. The stator is fed with AC to create a rotating magnetic field, and the rotor remains unconnected to the supply. Currents are induced in the rotor by this changing field, producing torque and motion. Because there’s no direct electrical connection to the rotor, there are no brushes or a commutator, leading to a rugged, maintenance-free design. This absence of brushes and armature is what sets induction motors apart from DC machines that rely on commutators and brushes.