Consider the following statements:
1. In an induction motor, when the number of stator slots is equal to an integral number of rotor slots, the machine may fail to start
2. The frame of an induction motor is made of cast iron
3. A three-phase slip ring induction motor is fed from the rotor side with the stator winding short-circuited. The frequency of the current flowing in the short-circuited stator is Supply frequency
Which of the above statement(s) is/are correct?
1
Only 2
2
All are correct
3
Only 1 and 2
4
Only 2 and 3