Electrical Machines The speed of a 50 Hz three phase induction motor under full load condition is 725 rpm the number of poles of the motor are ______________. 6. 4. 8. 2. 6. 4. 8. 2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will improve with fall of terminal voltage. deteriorate with rise in terminal voltage. improve with rise in terminal voltage. deteriorate with fall of terminal voltage. improve with fall of terminal voltage. deteriorate with rise in terminal voltage. improve with rise in terminal voltage. deteriorate with fall of terminal voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 2, 3, 4 1, 2, 3, 4 1, 2, 5 1, 3, 5 2, 3, 4 1, 2, 3, 4 1, 2, 5 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The main disadvantage(s) of the ward-Leonard system is/are all of above. high initial cost. high maintenance cost. poor overall efficiency. all of above. high initial cost. high maintenance cost. poor overall efficiency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A generator may loose residual magnetism due to vibrations. any of these. over excitation. heating. vibrations. any of these. over excitation. heating. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Generator works on the principle of production dynamically induced emf. both A and B. None of these static induced emf. dynamically induced emf. both A and B. None of these static induced emf. ANSWER DOWNLOAD EXAMIANS APP