13 Most Important Questions and Answers on AC Motor - Part-1

Figure: Asynchronous AC Motor (Induction)

Q1. What are the three basic types of ac motors?

A1. Series, synchronous, induction.

Q2. Series motors are generally used to operate what type of equipment?

A2. To power small appliances.

Q3. Why are series motors sometimes called universal motors?

A3. They operate on either ac or dc.

Q4. What determines the number of field poles required to establish a rotating magnetic field in a multiphase motor stator?

A4. The number of phases in the applied voltage.

Q5. What is the angular displacement between field poles in a two-phase motor stator?

A5. 90º .

Q6. What is the major difference between a two-phase and a three-phase stator?

A6. Number and location of field poles.

Q7. What requirement is the synchronous motor specifically designed to meet?

A7. Constant speed required by some loads.

Q8. Why is the ac induction motor used more often than other types?

A8. They are simple and inexpensive to make.

Q9. The speed of the rotor is always somewhat less than the speed of the rotating field. What is the difference called?

A9. Slip.

Q10. What determines the amount of slip in an induction motor?

A10. Load.

Q11. What type of ac motor is most widely used?

A11. Single-phase induction motor.

Q12. How do split-phase induction motors become self-starting?

A12. By using combinations of inductance and capacitance to apply out-of phase currents in starting windings.

Q13. Why are shaded-pole motors used to drive only very small devices?

A13. They have very weak starting torques.

Download this Article as PDF:

Related Post: 

1. 18 Most Important Questions and Answers on DC Motors - Part-1.
2. 10 Interview Questions and Answers on Motor - Part-2

comments