Slip rings are usually made of___________?

Related Mcqs:

The injected e.m.f. in the rotor of induction motor must have__________?

A. zero frequency B. the same frequency as the slip frequency C. the same phase as the rotor e.m.f. D. high value for the satisfactory speed control...

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...

Short-circuit test on an induction motor cannot be used to determine___________?

A. windage losses B. copper losses C. transformation ratio D. power scale of circle diagram...

The low power factor of induction motor is due to___________?

A. rotor leakage reactance B. stator reactance C. the reactive lagging magnetizing current necessary to generate the magnetic flux D. all of the above...

In a squirrel cage motor the induced e.m.f. is___________?

A. dependent on the shaft loading B. dependent on the number of slots C. slip times the stand still e.m.f. induced in the rotor D. none of the above...