Electrical Machines What is the necessity of copper brushes in a dc motors? To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole wave wound dc motor having flux per pole of 9.56 X 10-3 Wb contains 460 armature conductors. Calculate the back emf produced when it is running at a speed of 1500 rpm. 240 volt. 440 volt. 220 volt. 230 volt. 240 volt. 440 volt. 220 volt. 230 volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchronous motor is supplying a load at unity power factor. If the load on the motor is increased keeping its excitation and terminal voltage constant, the power factor will become leading None of these will become lagging will remain the same will become leading None of these will become lagging will remain the same ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The stator core of a 3 - Φ induction motor is laminated in order to reduce the eddy current loss. hysteresis loss. weight of the stator. both of the above. eddy current loss. hysteresis loss. weight of the stator. both of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. Both of above. None of these. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. Both of above. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine yoke offers mechanical protection to the machine produce working flux both A and B flux path completion mechanical protection to the machine produce working flux both A and B flux path completion ANSWER DOWNLOAD EXAMIANS APP
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