Lubricant used for ball bearing is usually___________?

Related Mcqs:

1. Which type of bearing is provided in small induction motors to support the rotor shaft ?

   A. Ball bearings
   B. Cast iron bearings
   C. Bush bearings
   D. None of the above

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

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

3. Star-delta starting of motors is not possible in case of____________?

   A. single phase motors
   B. variable speed motors
   C. low horse power motors
   D. high speed motors

4. 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

5. For which motor the speed can be controlled from rotor side ?

   A. Squirrel-cage induction motor
   B. Slip-ring induction motor
   C. Both A. and (b)
   D. None of the above

6. Size of a high speed motor as compared to low speed motor for the same H.P. will be__________?

   A. bigger
   B. smaller
   C. same
   D. any of the above

7. A 3-phase slip ring motor has____________?

   A. double cage rotor
   B. wound rotor
   C. short-circuited rotor
   D. any of the above

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. Blocked rotor test on induction motors is used to find out?

   A. leakage reactance
   B. power factor on short circuit
   C. short-circuit current under rated voltage
   D. all of the above

10. 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