Electrical Machines If the temperature of armature resistance is increased, the speed of a series motor would not change. decrease. None of above. increase. not change. decrease. None of above. increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and flux of a DC motor are held constant and voltage applied across it armature is increased by 5%, the speed of the motor will Increase by 5%. Depends on other factor. Remain unchanged. Reduce by 5%. Increase by 5%. Depends on other factor. Remain unchanged. Reduce by 5%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator in DC machines can 1. provide half-wave rectification 2. Provide full-wave rectification 3. convert ac to dc 4. Convert dc to ac 5. provide controlled full-wave rectification From these, the correct answer is 2, 3, 4, 5 2, 3 ,5 1, 2, 3 2, 3, 4 2, 3, 4, 5 2, 3 ,5 1, 2, 3 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The air gap between the yoke and armature is dc machine is kept very small to avoid locking of the armature. All of these to achieve a stronger magnetic field. to avoid over heating. to avoid locking of the armature. All of these to achieve a stronger magnetic field. to avoid over heating. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cogging and crawling are phenomena associated with the former at a fraction of its rate speed and the latter during starting. the former during starting and the latter at a fraction of its rated speed. any of the above. cage induction machines and they are essentially the same. the former at a fraction of its rate speed and the latter during starting. the former during starting and the latter at a fraction of its rated speed. any of the above. cage induction machines and they are essentially the same. 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 rise in terminal voltage. deteriorate with fall of terminal voltage. deteriorate with rise in terminal voltage. improve with fall of terminal voltage. improve with rise in terminal voltage. deteriorate with fall of terminal voltage. deteriorate with rise in terminal voltage. improve with fall of terminal voltage. ANSWER DOWNLOAD EXAMIANS APP
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