Electrical Machines In DC generators, the residual magnetism is of the order of 15 %. 20 %. 2.5 %. 10 %. 15 %. 20 %. 2.5 %. 10 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If starter is not used with large DC motor for starting, it will provide execessive voltage drop in line. draw a starting current many times its rated full load current. all of above. damage the armature and commutator. provide execessive voltage drop in line. draw a starting current many times its rated full load current. all of above. damage the armature and commutator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the cause of rapid brush wear may be severe sparking. rough commutator surface. imperfect contact. any of above. severe sparking. rough commutator surface. imperfect contact. any of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the inequality of air-gap flux on the top and bottom halves of the armature is removed a counter-emf is induced in the coil undergoing commutation the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics the inequality of air-gap flux on the top and bottom halves of the armature is removed a counter-emf is induced in the coil undergoing commutation the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, for the same value of Æ, Z and N; which one of the following statements is correct? Armature emf is more with wave winding than with lap winding. Armature emf depends on weather the machine is running as a motor or generator. Armature emf is less with wave winding than with lap winding. Armature emf is same as long as the flux density in the air gap remains the same. Armature emf is more with wave winding than with lap winding. Armature emf depends on weather the machine is running as a motor or generator. Armature emf is less with wave winding than with lap winding. Armature emf is same as long as the flux density in the air gap remains the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions hunting of synchronous motor is likely to occur ? Small and constant load. Over-loading for long period. Over-excitation. Periodic variation of load. Small and constant load. Over-loading for long period. Over-excitation. Periodic variation of load. ANSWER DOWNLOAD EXAMIANS APP
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