1.(a) What is meant by the slip of an induction motor

(b) The rotor of a four-pole three-phase induction motor revolves at 1380 r/min.

The slip is 8%. Find the supply frequency.

2.Calculate the frequency of the rotor EMF for each of the machines of Exercises 7, 8 and 9.

3. (a) Why can’t an induction motor run at synchronous speed?

(b) A six-pole, 50 Hz three-phase induction motor runs with 5% slip. What is its speed? What is the frequency of the rotor current?

4. A four-pole 50 Hz three-phase induction motor runs with 4% slip at full load. What will be the frequency of the current induced in the rotor (a) at starting and

(b) at full load?