A change of 4% of supply voltage to an induction motor will produce a change of approximately ________?

Related Mcqs:

1. A pump induction motor is switched on to a supply 30% lower than its rated voltage. The pump runs. What will eventually happen ? It will____________?

   A. stall after sometime
   B. stall immediately
   C. continue to run at lower speed without damage
   D. get heated and subsequently get damaged

2. Slip ring motor is preferred over squirrel cage induction motor where___________?

   A. high starting torque is required
   B. load torque is heavy
   C. heavy pull out torque is required
   D. all of the above

3. The shaft of an induction motor is made of_____________?

   A. high speed steel
   B. stainless steel
   C. carbon steel
   D. cast iron

4. A double squirrel-cage induction motor has______________?

   A. two rotors moving in oppsite direction
   B. two parallel windings in stator
   C. two parallel windings in rotor
   D. two series windings in stator

5. When the equivalent circuit diagram of doouble squirrel-cage induction motor is constructed the two cages can be considered__________?

   A. in series
   B. in parallel
   C. in series-parallel
   D. in parallel with stator

6. 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

7. 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

8. The starting torque of a 3-phase squirrel cage induction motor is____________?

   A. twice the full load torque
   B. 1.5 times the full load torque
   C. equal to full load torque

9. An induction motor can run at synchronous speed when____________?

   A. it is run on load
   B. it is run in reverse direction
   C. it is run on voltage higher than the rated voltage
   D. e.m.f. is injected in the rotor circuit

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

    A. resistance rise method
    B. thermometer method
    C. embedded temperature method
    D. all above methods