1. Show that a rotating magnetic field is produced in the air-gap, when a balanced Three-
phase ac supply is given to the stator of a 3-phase induction motor. Justify Your claim with
necessary mathematical equations
2. With the help of neat sketch, explain the constructional features of a three-phase induction
motors. Explain the differences between sq. cage IM & Slip ring IM.
3. Explain why the rotor of poly phase induction motor can never attain Synchronous speed
4. Discuss the phenomenon of crawling & cogging in an induction motor
5. Explain necessary steps to construct the circle-diagram
6. Draw and explain the phasor diagram & equivalent circuit of 3-phase induction motor.
7. Explain the terms air gap power Pg, internal mechanical power developed Pm
and shaft power Psh. How these terms are are related with each other?
Hence show that Pg: rotor ohmic loss: Pm = l: s: 1-s.
8. Write short notes on:
i) Double cage and ii) Deep bar Rotors.
9. Explain speed control of induction motor by using different methods
10. Discuss the points of similarities between a transformer and an induction machine. Hence,
explain why an induction machine is called a generalized transformer.
11. With neat diagram the explain Torque-Slip characteristics of three phase
Induction motor