Electrical Machines The sparking at the the brushes, in a DC machines is due to high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic field which initially induces emf in the armature in a self excited DC generator is because of residual magnetism. None of these armature reaction. permanent magnets. residual magnetism. None of these armature reaction. permanent magnets. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately excited DC motor has an armature resistance of 0.5 Ohm. The supply voltage is 250V. Armature current is 20A and the speed of rotation is 1500 rpm. Find the torque developed? 15.28 Nm 15.6 Nm 16.55 Nm Zero 15.28 Nm 15.6 Nm 16.55 Nm Zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the mechanical angle α between the stator and rotor poles increases, then the stator current None of above. Increases. Remains unchanged. Decreases. None of above. Increases. Remains unchanged. Decreases. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In auto transformer if the turn ratio is K, what is the power transferred inductively? None of these both A and B K × input power (1-K) × input power None of these both A and B K × input power (1-K) × input power ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the air gap of IM is increased, ____________ will increase. power factor. magnetizing current. air gap flux. speed. power factor. magnetizing current. air gap flux. speed. ANSWER DOWNLOAD EXAMIANS APP
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