Electrical Machines Interpoles in a DC motor must be Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous motor hunting can be reduced to minimum possible by designing the motor for adequate synchronizing power. any of above methods. providing damper winding in the rotor pole faces. using a flywheel. designing the motor for adequate synchronizing power. any of above methods. providing damper winding in the rotor pole faces. using a flywheel. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 2, 4 1, 4 1, 3 2, 3 2, 4 1, 4 1, 3 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines During hunting of a synchronous motor damper bar develops torque. field excitation increases. negative phase sequence currents are generated. harmonic are developed in the armature circuit. damper bar develops torque. field excitation increases. negative phase sequence currents are generated. harmonic are developed in the armature circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For small value armature current Ia the torque developed by a DC series motor is proportional to Ia2. 1/Ia. Ia. √Ia. Ia2. 1/Ia. Ia. √Ia. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct axis reactance is defined as the ratio of Vmax to Imin Vmin to Imin Vmin to Imax Vmax to Imax Vmax to Imin Vmin to Imin Vmin to Imax Vmax to Imax ANSWER DOWNLOAD EXAMIANS APP