Electrical Machines Consider a separately excited DC motor. If the field current is increased while the armature terminal voltage is held constant, then speed of the motor None of these. Remains same. Decrease. Increase. None of these. Remains same. Decrease. Increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The slip of an induction motor normally does not depend on synchronous speed. rotor speed. shaft torque. core loss component. synchronous speed. rotor speed. shaft torque. core loss component. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a DC motor can be determined by Lenz's law. Fleming's left hand rule. Ampere's law. Fleming's right hand rule. Lenz's law. Fleming's left hand rule. Ampere's law. Fleming's right hand rule. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 1, 2, 5 1, 2, 3, 4 1, 3, 5 2, 3, 4 1, 2, 5 1, 2, 3, 4 1, 3, 5 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an AC servomotor has one of its winding excited by AC, then voltage measured at the other winding with rotor running will be constant independent of speed. proportional to square of rotor speed. zero. proportional to rotor speed. constant independent of speed. proportional to square of rotor speed. zero. proportional to rotor speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines During hunting of a synchronous motor field excitation increases. negative phase sequence currents are generated. harmonic are developed in the armature circuit. damper bar develops torque. field excitation increases. negative phase sequence currents are generated. harmonic are developed in the armature circuit. damper bar develops torque. ANSWER DOWNLOAD EXAMIANS APP
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