The efficiency of an induction motor can be expected to be nearly____________?

Related Mcqs:

1. 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

2. The torque of an induction motor is___________?

   A. directly proportional to slip
   B. inversely proportional to slip
   C. proportional to the square of the slip
   D. none of the above

3. An induction motor with 1000 r.p.m. speed will have____________?

   A. 8 poles
   B. 6 poles
   C. 4 poles
   D. 2 poles

4. Which of the following methods is easily applicable to control the speed of the squirrel-cage induction motor _____________?

   A. By changing the number of stator poles
   B. Rotor rheostat control
   C. By operating two motors in cascade
   D. By injecting e.m.f. in the rotor circuit

5. The torque developed in the cage induction motor with autostarter is___________?

   A. k/torque with direct switching
   B. K x torque with direct switching
   C. K2 x torque with direct switching
   D. k2/torque with direct switching

6. The speed of a squirrel-cage induction motor can be controlled by all of the following except_____________?

   A. changing supply frequency
   B. changing number of poles
   C. changing winding resistance
   D. reducing supply voltage

7. As load on an induction motor goes on increasing______________?

   A. its power factor goes on decreasing
   B. its power factor remains constant
   C. its power factor goes on increasing even after full load
   D. its power factor goes on increasing up to full load and then it falls again

8. The power scale of circle diagram of an induction motor can be found from__________?

   A. stator resistance test
   B. no-load test only
   C. short-circuit test only
   D. noue of the above

9. In induction motor, percentage slip depends on__________?

   A. supply frequency
   B. supply voltage
   C. copper losses in motor
   D. none of the above

10. Insertion of resistance in the rotor of an induction motor to develop a given torque?

    A. decreases the rotor current
    B. increases the rotor current
    C. rotor current becomes zero
    D. rotor current rernains same