Which of the following is a component of a typical three-phase squirrel-cage motor?

A typical three-phase squirrel-cage motor consists of several key components, with the rotor being one of the most essential. The rotor is the rotating part of the motor that converts electrical energy into mechanical energy. In a squirrel-cage motor, the rotor is formed from conductive bars shorted at both ends by end rings, resembling a "squirrel-cage." This design is crucial for inducing current within the rotor when it’s placed in a magnetic field generated by the three-phase stator. The interaction of the magnetic fields causes the rotor to turn and produce movement, making the rotor fundamental to the motor's operation.

The other components mentioned, such as the commutator, inductor, and capacitor, are not parts of a squirrel-cage motor. The commutator is typically found in DC motors to reverse current direction in the rotor, while inductors and capacitors may be used in different applications or types of motors but are not intrinsic to a squirrel-cage design. Hence, the rotor is identified as the core component unique to this type of motor.