Electrical Machines The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that Eb is unchanged, but Td is zero both Eb and Td are unchanged Eb is zero, but Td is unchanged both Eb and Td are zero Eb is unchanged, but Td is zero both Eb and Td are unchanged Eb is zero, but Td is unchanged both Eb and Td are zero 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 voltage magnitude same prime mover speed same phase sequence same frequency same voltage magnitude same prime mover speed same phase sequence same frequency ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine 72 number of coils are used. Find the number of commutator segments required? 74 36 37 72 74 36 37 72 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is critical, the power factor of the alternator is unity power factor. lagging power factor. leading power factor. None of these unity power factor. lagging power factor. leading power factor. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings are used in DC generators to provide path for the circulation of cooling air. mainly to reduce the eddy currents by providing local short circuit. None of these to neutralize the cross magnetizing effect of the armature reaction. to provide path for the circulation of cooling air. mainly to reduce the eddy currents by providing local short circuit. None of these to neutralize the cross magnetizing effect of the armature reaction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines At stand still condition the value of slip is finite value 1 infinite value 0 finite value 1 infinite value 0 ANSWER DOWNLOAD EXAMIANS APP
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