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 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 Eb is zero, but Td is unchanged both Eb and Td are unchanged ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in a DC machine is in the same direction as the main poles. makes an angle of 90° with the main pole axis. is in direct opposition to the main poles. makes an angle with the main pole axis which is load dependent. is in the same direction as the main poles. makes an angle of 90° with the main pole axis. is in direct opposition to the main poles. makes an angle with the main pole axis which is load dependent. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For the speed control of polyphase squirrel cage induction motor, if frequency of operation is decreased with constant supply voltage V, starting torque Tst decreases constant V, Tst increases either of these None of these constant supply voltage V, starting torque Tst decreases constant V, Tst increases either of these None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings are used in DC generators to provide path for the circulation of cooling air. mainly to reduce the eddy currents by providing local short circuit. to neutralize the cross magnetizing effect of the armature reaction. None of these to provide path for the circulation of cooling air. mainly to reduce the eddy currents by providing local short circuit. to neutralize the cross magnetizing effect of the armature reaction. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which motors are preferred for refrigeration and air conditioning in smaller units? Stepper motors. Universal motors. Induction motors. Reluctance motors. Stepper motors. Universal motors. Induction motors. Reluctance motors. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The effect of ------------------ on main field flux is armature reaction? All of these armature current armature mmf armature flux All of these armature current armature mmf armature flux ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS