Electrical Machines The material used for commutator brushes is mostly cast iron. mica. carbon. copper. cast iron. mica. carbon. copper. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor has synchronous speed of 1500 rpm. What will be the slip when it is running at a speed of 1450 rpm? -3% +3% -3.33% +3.33% -3% +3% -3.33% +3.33% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Open circuit test on transformer gives copper loss both 1and 2 eddy current loss hysteresis loss copper loss both 1and 2 eddy current loss hysteresis loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Why are capacitors used with large AC induction motor? Improve voltage level. Improve current level. Improve power factor. Improve power level. Improve voltage level. Improve current level. Improve power factor. Improve power level. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous motor hunting can be reduced to minimum possible by using a flywheel. designing the motor for adequate synchronizing power. providing damper winding in the rotor pole faces. any of above methods. using a flywheel. designing the motor for adequate synchronizing power. providing damper winding in the rotor pole faces. any of above methods. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 1 and 3 1, 2 and 4 2, 3 and 4 1, 2, and 3 1 and 3 1, 2 and 4 2, 3 and 4 1, 2, and 3 ANSWER DOWNLOAD EXAMIANS APP