What are Asynchronous Motors most commonly referred to as?

Asynchronous motors are most commonly referred to as induction motors because they operate on the principle of electromagnetic induction. In these motors, the rotor does not rotate at the same speed as the magnetic field produced by the stator but instead "induces" current to create motion. This creation of torque from induced currents in the rotor distinguishes induction motors from other types of motors.

Induction motors are renowned for their robustness, simplicity, and efficiency in a variety of applications, making them one of the most widely used types of electric motors in industrial and commercial settings. The term “asynchronous” specifically refers to the fact that the rotor speed is slightly less than the synchronous speed of the magnetic field, which is a defining characteristic of these motors.

Other types of motors listed in the options have distinct operational principles; for example, universal motors can run on either alternating current (AC) or direct current (DC), direct current motors convert electrical energy directly into mechanical energy without induction, and permanent magnet motors utilize permanent magnets to generate the magnetic field. This further underscores the unique classification of asynchronous motors as induction motors.