___________ brushes are fragile and cause excessive wear of commutator?

Related Mcqs:

Commercial available medium size machines have a speed range of __________ ?

A. 200 to 400 r.p.m B. 600 to 1000 r.p.m C. 1000 to 1500 r.p.m D. 2000 to 2500 r.p.m...

In self cooled motors the cooling time constant is about ___________ than the heating time constant because cooling conditions are worse at standstill?

A. 2 to 3 times greater B. 3 to 4 times greater C. 4 to 5 times greater D. none of the above...

The distance between the starts of two consecutive coils measured in terms of coil sides is called_____________?

A. front pitch B. winding pitch C. commutator pitch D. back pitch...

The stator of a D.C. machine comprises of_____________?

A. main poles B. interpoles C. frame D. all of the above...

The voltage control in electric supply networks in required on account of which of the following reasons ?

A. Adjustment of voltage at consumers premises within statutory limits B. Control of active and reactive power C. Adjustment of short period daily and seasonal voltage variations in accordance with variations of load D. All of the above...