Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 2, 4 1, 3 1, 4 2, 3 2, 4 1, 3 1, 4 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by a DC motor at the time of starting is Very high. Zero. Normal. Very low. Very high. Zero. Normal. Very low. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The shaft of induction motor should be stiff. any of these. flexible. hollow. stiff. any of these. flexible. hollow. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator in DC machines can 1. provide half-wave rectification 2. Provide full-wave rectification 3. convert ac to dc 4. Convert dc to ac 5. provide controlled full-wave rectification From these, the correct answer is 2, 3, 4, 5 2, 3 ,5 2, 3, 4 1, 2, 3 2, 3, 4, 5 2, 3 ,5 2, 3, 4 1, 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single phase transformer when supplied from 220 V, 50 Hz has eddy current loss of 50 W. If the transformer is connected voltage of 330 V, 75 Hz, the eddy current loss will be 168.75 W 112.5 W 75 W 50 W 168.75 W 112.5 W 75 W 50 W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing divertor resistance of a DC series motor Increase in speed but armature currnet remains the same. Decrease in speed but armature current remains the same. Increase in speed demanding more armature current. Decrease in speed demanding less armature current. Increase in speed but armature currnet remains the same. Decrease in speed but armature current remains the same. Increase in speed demanding more armature current. Decrease in speed demanding less armature current. ANSWER DOWNLOAD EXAMIANS APP
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