Temperature of the stator winding of a three phase induction motor is obtained by___________?

Related Mcqs:

1. In a three-phase induction motor, the number of poles in the rotor winding is always__________?

   A. zero
   B. more than the number of poles in stator
   C. less than number of poles in stator
   D. equal to number of poles in stator

2. A 3-phase induction motor stator delta connected, is carrying full load and one of its fuses blows out. Then the motor_______________?

   A. will continue running burning its one phase
   B. will continue running burning its two phases
   C. will stop and carry heavy current causing permanent damage to its winding
   D. will continue running without any harm to the winding

3. If an induction motor with certain ratio of rotor to stator slots, runs at 1/7 of the normal speed, the phenomenon will be termed as____________?

   A. humming
   B. hunting
   C. crawling
   D. cogging

4. In an induction motor the relationship between stator slots and rotor slots is that_____________?

   A. stator slots are equal to rotor slots
   B. stator slots are exact multiple of rotor slots
   C. stator slots are not exact multiple of rotor slots
   D. none of the above

5. What will happen if the relative speed between the rotating flux of stator and rotor of the induction motor is zero ?

   A. The slip of the motor will be 5%
   B. The rotor will not run
   C. The rotor will run at very high speed
   D. The torque produced will be very large

6. The starting torque of a three phase induction motor can be increased by__________?

   A. increasing slip
   B. increasing current
   C. both A. and (b)
   D. none of the above

7. The ‘crawling” in an induction motor is caused by___________?

   A. high loads
   B. low voltage supply
   C. improper design of machine
   D. harmonics developed in the motor

8. Insertion of resistance in the stator of an induction motor___________?

   A. increases the load torque
   B. decreases the starting torque
   C. increases the starting torque
   D. none of the above

9. A 500 kW, 3-phase, 440 volts, 50 Hz, A.C. induction motor has a speed of 960 r.p.m. on full load. The machine has 6 poles. The slip of the machine will be__________?

   A. 0.01
   B. 0.02
   C. 0.03
   D. 0.04

10. The torque developed by a 3-phase induction motor least depends on__________?

    A. rotor current
    B. rotor power factor
    C. rotor e.m.f.
    D. shaft diameter