What is primarily observed in a squirrel cage motor's rotor design?

In a squirrel cage motor's rotor design, the primary feature observed is a series of conductive bars that are typically made from aluminum or copper, connected at each end by short-circuiting end rings. This design forms a closed loop that is crucial for the operation of the motor. When alternating current flows through the stator winding, it creates a rotating magnetic field, which induces currents in the conductive bars of the rotor. The interaction between the rotating magnetic field and the induced currents generates torque, leading to the rotation of the rotor.

This design is favored for its robustness, simplicity, and efficiency. Unlike other motor designs that may use complex winding patterns or solid magnetic cores, the squirrel cage rotor is straightforward and requires minimal maintenance. The lack of external connections also reduces the potential for wear and tear, contributing to the overall reliability and lifespan of the motor. This makes option B the correct identification of what is primarily observed in a squirrel cage motor's rotor design.