Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 16.67 Hz. 60 Hz. 50 Hz. 25 Hz. 16.67 Hz. 60 Hz. 50 Hz. 25 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by s2. f / s. sf. sf / 2. s2. f / s. sf. sf / 2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 ,V 15 , kW 100 rpm shunt motor with armature resistance of 0.25 , W has a rated line current of 68 A and a rated field current of 2.2 A. The change in field flux required to obtain a speed of 1600 rpm while drawing a line current of 52.8 A and a field current of 1.8 A is 36.36% decrease 18.18% increase 36.36% increase 36.36% increase 36.36% decrease 18.18% increase 36.36% increase 36.36% increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutators in DC machines have a role of which converts Both AC to DC and DC to AC. high voltage DC to low voltage DC. AC to DC. none of these. Both AC to DC and DC to AC. high voltage DC to low voltage DC. AC to DC. none of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes All of these They are self lubricating in nature They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes All of these They are self lubricating in nature ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor is used in grinders? Capacitor start capacitor run IM. Synchronous motor. Capacitor start IM. Split phase IM. Capacitor start capacitor run IM. Synchronous motor. Capacitor start IM. Split phase IM. ANSWER DOWNLOAD EXAMIANS APP
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