Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.573. 0.649. 0.443. 0.512. 0.573. 0.649. 0.443. 0.512. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines With the increase in speed of DC motor Back emf falls and line current increase. Back emf increase but line current falls. Both back emf as well as line current increase. Both back emf as well as line current fall. Back emf falls and line current increase. Back emf increase but line current falls. Both back emf as well as line current increase. Both back emf as well as line current fall. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines No load test of 3-phase induction motor gives which of the following? variable loss None of these constant loss both A and B variable loss None of these constant loss both A and B ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are effects of armature reaction? increase the maintenance and repair increase the iron loss All of these increases the design cost increase the maintenance and repair increase the iron loss All of these increases the design cost ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a Dc generator the magnetic neutral axis coincide with geometrical neutral axis, when the generator runs on overload. the generator runs on full load. the generator runs on designed speed. there is no load on the generator. the generator runs on overload. the generator runs on full load. the generator runs on designed speed. there is no load on the generator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For satisfactory parallel operation of two transformers which of the following conditions is most essential, polarities of all transformers must be same. voltage ratio of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. percentage impedance of all transformers must be same. polarities of all transformers must be same. voltage ratio of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. percentage impedance of all transformers must be same. ANSWER DOWNLOAD EXAMIANS APP
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