Question

A.C. servomotor is basically a

(a) Universal motor

(b) Single phase induction motor

(c) Two phase induction motor

(d) Three phase induction motor

I had been asked this question in a national level competition.

Question is taken from Stability of Nonlinear System topic in portion Nonlinear Systems of Control Systems

Answer 1

The correct answer is:

(c) Two phase induction motor

Explanation:

An A.C. servomotor is typically a two-phase induction motor. It is designed to provide precise control of position, speed, and acceleration in control systems. These motors are often used in applications requiring fast response and high accuracy.

• Two-phase induction motors are widely used in servosystems because they can provide the necessary torque and speed control with high precision.
• Universal motors are capable of running on both AC and DC, but they are not commonly used in servomotor applications.
• Single-phase and three-phase induction motors are used for general-purpose drives but are not specifically designed for the fast, precise control required in servo applications.

Thus, two-phase induction motors are most commonly associated with A.C. servomotors.