Electrical Machines For satisfactory parallel operation of two transformers which of the following conditions is most essential, percentage impedance of all transformers must be same. voltage ratio of all transformers must be same. polarities of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. percentage impedance of all transformers must be same. voltage ratio of all transformers must be same. polarities of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 0.5 at 90°C. 2 at 90°C. 3 at 90°C. 1 at 90°C. 0.5 at 90°C. 2 at 90°C. 3 at 90°C. 1 at 90°C. 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? +3.33% -3% +3% -3.33% +3.33% -3% +3% -3.33% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by increasing field excitation. fixing the brush axis inline with the pole axis. shifting the brush axis from GNA to MNA. compensating winding and commutating poles. increasing field excitation. fixing the brush axis inline with the pole axis. shifting the brush axis from GNA to MNA. compensating winding and commutating poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines R1 is the resistance of the primary winding of the transformer. The turn ratio in terms of primary to secondary is K. Then the equivalent resistance of the primary referred to secondary is R1 /K² R1 /K K×R1 K²R1 R1 /K² R1 /K K×R1 K²R1 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Essential conditions for two DC generators are connecting for parallel operation is/are terminal voltage should be same. both A and B. rating of generators should be same. polarities should be same. terminal voltage should be same. both A and B. rating of generators should be same. polarities should be same. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS