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 1, 3 2, 4 1, 4 2, 3 1, 3 2, 4 1, 4 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to any of the above. too rapid reversal of current. under commutation. over commutation. any of the above. too rapid reversal of current. under commutation. over commutation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For high current and low voltage rating which winding is employed to DC machine? Lap winding. No wave and lap winding. Wave winding. Both wave and lap winding. Lap winding. No wave and lap winding. Wave winding. Both wave and lap winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Air core transformer as compared to iron core transformer, has less magnetic core loss. more copper loss. more magnetic core loss. no magnetic core loss. less magnetic core loss. more copper loss. more magnetic core loss. no magnetic core loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the speed of a dc motor increases with load torque, then it is a series motor comulatively compounded motor differentially compounded motor permanent magnet motor series motor comulatively compounded motor differentially compounded motor permanent magnet motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under commutation results in no sparking. sparking at the leading edge of the brush. sparking the trailing edge of the brush. sparking at the middle of the brush. no sparking. sparking at the leading edge of the brush. sparking the trailing edge of the brush. sparking at the middle of the brush. ANSWER DOWNLOAD EXAMIANS APP
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