Electrical Machines The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that Eb is zero, but Td is unchanged both Eb and Td are unchanged both Eb and Td are zero Eb is unchanged, but Td is zero Eb is zero, but Td is unchanged both Eb and Td are unchanged both Eb and Td are zero Eb is unchanged, but Td is zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Resistance commutation is used generally in case of None of these DC machines above 10 kW. DC machines bellow 5 kW. fractional kW DC machines. None of these DC machines above 10 kW. DC machines bellow 5 kW. fractional kW DC machines. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To avoid formation of grooves in the commutator brush position has no effect on the commutator grooving. the brushes of same polarity should track each other. the brushes of opposite polarity should track each other. None of these brush position has no effect on the commutator grooving. the brushes of same polarity should track each other. the brushes of opposite polarity should track each other. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a DC series motor is Inversely proportional to the armature current. Proportional to the armature current. Proportional to the square of the armature current. Proportional to field current. Inversely proportional to the armature current. Proportional to the armature current. Proportional to the square of the armature current. Proportional to field current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In Ward-Leonard system, the lower limit of the speed imposed by Residual magnetism of the generator. Field resistance. Armature resistance. None of above. Residual magnetism of the generator. Field resistance. Armature resistance. None of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The overall power factor of an on load transformer is always lagging. depends on the power factor of the load. is always leading. is always unity. is always lagging. depends on the power factor of the load. is always leading. is always unity. ANSWER DOWNLOAD EXAMIANS APP