Electrical Machines Secondary winding of an auto transformer is also called compensating winding. tertiary winding. common winding. damping winding. compensating winding. tertiary winding. common winding. damping winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a 3-phase induction motor operating in its stable region remains constant. decreases with increase in the load torque. increases with increase in the load torque. decreases with decrease in the load torque. remains constant. decreases with increase in the load torque. increases with increase in the load torque. decreases with decrease in the load torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC motor with armature resistance of 0.5 ohms connected directly to a 220 Volt supply. If the armature is stationary then the current flowing through the armature is 250 A. 340 A. 570 A. 440 A. 250 A. 340 A. 570 A. 440 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Interpoles in a DC motor must be Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 1, 2, 5 2, 3, 6 3, 4, 5 2, 4, 5, 6 1, 2, 5 2, 3, 6 3, 4, 5 2, 4, 5, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An ideal synchronous motor has no starting torque because relative velocity between stator and rotor mmf’s is not zero. rotor winding is highly reactive. rotor is made up of salient poles. relative velocity between the stator and rotor mmf’s is zero. relative velocity between stator and rotor mmf’s is not zero. rotor winding is highly reactive. rotor is made up of salient poles. relative velocity between the stator and rotor mmf’s is zero. ANSWER DOWNLOAD EXAMIANS APP
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