Copper brushes in D.C. machine are used_____________?

Related Mcqs:

Iron losses in a D.C. machine are independent of variations in______________?

A. speed B. load C. voltage D. speed and voltage...

D.C. generators are connected to the busbars or disconnected from them only under the floating condition________________?

A. to avoid sudden loading of the primemover B. to avoid mechanicaljerk to the shaft C. to avoid burning of switch contacts D. all above...

The demagnetising component of armature reaction in a D.C. generator___________?

A. reduces generator e.m.f. B. increases armature speed C. reduces interpoles flux density D. results in sparking trouble...

In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis, when_______________?

A. there is no load on|he generator B. the generator runs on full load C. the generator runs on overload D. the generator runs on designed speed...

A series generator can self-excite:______________?

A. only if the load current is zero B. only if the load current is not zero C. irrespective of the value of load current D. none of the above...