Electrical Machines A DC Shunt Motor having shunt field resistance of 250 Ω and armature resistance of 0.5 Ω is connected to 250 V supply and load current of 21 A. What is the back emf generated ? 240 V. 210 V 150 V. 230 V. 240 V. 210 V 150 V. 230 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the armature current of 5 Amp is flowing through the dc motor the torque produced is 47 Nm. Keeping the speed constant if the armature current is increased to 7 amp, calculate the new torque. Assume losses to be constant. 38.5 Nm. 74 Nm. 27.73 Nm . 65.8 Nm. 38.5 Nm. 74 Nm. 27.73 Nm . 65.8 Nm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 volt dc series motor having an armature resistance of 0.2 Ω takes a load current of 60 A. What will be the torque produced at the shaft of the motor? Consider brush drop of 1V. 133.22 N-m 266.20 N-m. 234.76 N-m. can not be determined. 133.22 N-m 266.20 N-m. 234.76 N-m. can not be determined. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motors has low ratings only? Capacitor start Resistance split phase Shaded pole Capacitor run Capacitor start Resistance split phase Shaded pole Capacitor run ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines No load test of 3-phase induction motor gives which of the following? variable loss None of these constant loss both A and B variable loss None of these constant loss both A and B ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What happens if fifth multiples of harmonics is given to induction motor? It will rotates in reverse direction. Either short circuit or open circuit occurs. Fail to start. It will rotates in normal operation. It will rotates in reverse direction. Either short circuit or open circuit occurs. Fail to start. It will rotates in normal operation. ANSWER DOWNLOAD EXAMIANS APP
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