Electrical Machines What is the necessity of copper brushes in a dc motors? To absorb the mechanical shocks produced during running condition. To increase the flux cutting by the rotor. To convert alternating supply current to direct current. None of these. To absorb the mechanical shocks produced during running condition. To increase the flux cutting by the rotor. To convert alternating supply current to direct current. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer maximum flux density is not constant, the eddy current loss varies as f V² V f² f V² V f² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator the emf generated by the armature is maximum when rate of change of flux is minimum. induced voltage is high. rate of change of flux is maximum. shaft rotation is high. rate of change of flux is minimum. induced voltage is high. rate of change of flux is maximum. shaft rotation is high. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Inserting an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. Inserting resistance to armature circuit and field circuit. Any of above. Inserting an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. Inserting resistance to armature circuit and field circuit. Any of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is not a necessary condition to be satisfied for synchronising an incoming alternator to an already operating alternator? same phase sequence same frequency same prime mover speed same voltage magnitude same phase sequence same frequency same prime mover speed same voltage magnitude ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a transformer to be tested at full load conditions but consuming only losses from the main, we do back to back test load test None of these OC and SC tests back to back test load test None of these OC and SC tests ANSWER DOWNLOAD EXAMIANS APP
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