Satisfactory commutation of D.C. machines requires______________?

Related Mcqs:

Fleming’s right-hand rule regarding direction of induced e.m.f., correlates__________?

A. magnetic flux, direction of current flow and resultant force B. magnetic flux, direction of motion and the direction of e.m.f. induced C. magnetic field strength, induced voltage and current D. magnetic flux, direction of force and direction of motion of conductor...

Brushes of D.C. machines are made of_________?

A. carbon B. soft copper C. hard copper D. all of above...

The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be_____________?

A. 640 V B. 620 V C. 600 V D. 580 V...

Two generators A and B have 6-poles each. Generator A has wave wound armature while generator B has lap wound armature. The ratio of the induced e.m.f. is generator A and B will be_______________?

A. 2 : 3 B. 3 : 1 C. 3 : 2 D. 1 : 3...

In a D.C. generator the number of mechanical degrees and electrical degrees will be the same when____________?

A. r.p.m. is more than 300 B. r.p.m. is less than 300 C. number of poles is 4 D. number of poles is 2...