Copper brushes in D.C. machine are used? Mark as favorite Copy Link where low voltage and high currents are involved where high voltage and small currents are involved in both of the above cases in none of the above cases Check Answer
While applying Fleming’s right-hand rule to find the direction of induced e.m.f., the thumb points towards? Mark as favorite Copy Link direction of induced e.m.f. direction of flux direction of motion of the conductor if forefinger points in the direction of generated e.m.f. direction of motion of conductor, if forefinger points along the lines of flux Check Answer
Which of the following could be lamina-proximately the thickness of laminations of a D.C. machine? Mark as favorite Copy Link 0.005 mm 0.06mm 0.6.m 5 m Check Answer
The field coils of D.C. generator are usually made of? Mark as favorite Copy Link mica cast iron copper carbon Check Answer
The armature of D.C. generator is laminated to? Mark as favorite Copy Link reduce the bulk provide the bulk insulate the core reduce eddy current loss Check Answer
ln a commutator? Mark as favorite Copy Link copper is harder than mica mica and copper are equally hard mica is harder than copper none of the above Check Answer
The commutator segments are connected to the armature conductors by means of? Mark as favorite Copy Link copper lugs resistance wires insulation pads brazing Check Answer
ln a four-pole D.C. machine? Mark as favorite Copy Link all the four poles are north poles alternate poles are north and south all the four poles are south poles two north poles follow two south poles Check Answer
Requirement of speed at which machine is driven is? Mark as favorite Copy Link more critical in the case of altenators more critical in the case of D.C. generators equally critical in the case of alternators as well as D.C. generators none Check Answer
Fleming’s right-band rule regarding direction of induced e.m.f., correlates? Mark as favorite Copy Link magnetic flux, direction of current flow and resultant force magnetic flux, direction of motion and the direction of e.m.f. induced magnetic field strength, induced voltage and current magnetic flux, direction of force and direction of motion of conductor Check Answer