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 ,5 2, 3, 4 2, 3, 4, 5 1, 2, 3 2, 3 ,5 2, 3, 4 2, 3, 4, 5 1, 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Fifth harmonic component of the induced voltage in three phase AC generator can be eliminated by using a winding pitch of 4 / 5. 5 / 6. 6 / 7. 2 / 3. 4 / 5. 5 / 6. 6 / 7. 2 / 3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because 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 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 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For which of the following loads, armature reaction is magnetizing in nature? pure resistive load pure inductive load pure capacitive load None of these pure resistive load pure inductive load pure capacitive load None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine 4 pole lap winding is used. The number of parallel paths are? 4 8 2 1 4 8 2 1 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Autotransformer makes effective saving on copper and copper losses, when its transformation ratio is equal to greater than one. very low approx to one. less than one. greater than one. very low approx to one. less than one. ANSWER DOWNLOAD EXAMIANS APP
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