AC Motor Questions and Answers for Viva

Answer-1: An AC motor or alternating current motor is an electric motor that consists of a stator with a coil that is supplied with alternating current to convert electric current into mechanical power.

Answer-2: AC motors are a power source for a wide variety of applications due to their flexibility, efficiency, and noiseless operation. They are used on pumps, water heaters, garden equipment, ovens, off road equipment and are commonly found in many appliances, equipment, and tools.

Answer-3: There are two types of AC motors, which are synchronous and induction.

Answer-4: In a synchronous motor, the rotation of the shaft is at the same pace as the frequency of the applied current with multiphase AC electromagnets on the stator that produce a rotating magnetic field.

Answer-5: An induction motor, or asynchronous motor, is a single excited motor where current is applied to one part of the motor, the stator. Flux from the stator cuts the short circuited coil in the rotor, which feels torque that makes the rotor rotate.

Answer-6: The stator produces a rotating magnetic field. It has a solid metal axle, a loop of wire, coils, squirrel cage, and interconnections.

Answer-7: The rotor is the part of an AC motor that moves or rotates. Rotar is the rotating part in ac motor; unlike a DC motor, the rotor on an AC motor does not have any connection with the external power source. It receives its power from the stator.

Answer-8: The AC motor were first invented by Nikola Tesla when he identified the rotating magnetic induction (RMF) field principle, which is used in alternators.

Answer-9: The main benefit of an AC motor is its ability to produce constant torque up to the rated speed.

Answer-10: The main components of an AC motor are the stator, stationary outer drum, and the rotor, the rotating inner portion attached to the motor shaft.

Answer-11: Single phase AC motors are used where there is a single phase supply. A single phase motor has one main winding and one auxiliary winding, which is perpendicular to the main winding.

Answer-12: Polyphase Motors, or many phase motors, are a type of AC motor that can be two or three phase and are similar to single phase motors in how they operate. A polyphase system can be two, three, or six phase with the majority being three phase.

Answer-13: Reluctance motors are a single phase motor, which operate with an accurate value of rotating magnetic field without any synchronous speed. The motor uses reluctance of torque to operate, a type of torque in iron devices.

Answer-14: The unique nature of the rotor of a hysteresis motor is what makes it different from other AC motors. The rotor contains semi-permanent magnetic material. Torque is created by the magnetic flux lagging behind the external magnetizing force.

Answer-15: A repulsion motor is a type of single phase motor that works by the repulsion of similar poles. Aside from the rotor and stator, a repulsion motor has a commutator brush assembly.

Answer-16: An asynchronous motor uses an induced current in its rotor to produce rotatory motion. This is the most common of the AC motors since it relies on AC current that is connected to the stator for its power supply. All of the power for an asynchronous motor is connected to the stator which comes from induction.

Answer-17: AC motors are used for a wide variety of industrial applications because of their strength, adaptability, endurance, and simplicity of design, which makes for easy maintenance.