Electrical Machines The sparking at the the brushes, in a DC machines is due to high resistance of carbon brushes. presence of commutator. armature reaction. reactance voltage. high resistance of carbon brushes. presence of commutator. armature reaction. reactance voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuit test is performed on a transformer with a certain impressed voltage at rated frequency. If the short circuit test is now performed with the same magnitude of impressed voltage, but at frequency higher than the rated frequency then The magnitude will both increase. The magnitude of circuit as well as the power factor will decrease. The magnitude of current will decrease but the power factor will increase. The magnetude of current will increase, but power factor will decrease. The magnitude will both increase. The magnitude of circuit as well as the power factor will decrease. The magnitude of current will decrease but the power factor will increase. The magnetude of current will increase, but power factor will decrease. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are 4% and 5% from no load to full load. Consider the governors operating at 50Hz on no load. How will the machine share, if the load is 600 MW? generator 1 gets over load generator 2 gets over load 200 MW and 400MW None of these generator 1 gets over load generator 2 gets over load 200 MW and 400MW None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc generator operating on load with its brushes on the geometrical neutral axis (GNA), the magnetic neutral axis (MNA) is shifted in the direction of rotation. Now, if the brushes are given a lead of 90° (electrical), then the MNA will shift forward by more than 90° shift forward by 90° shift forward by less than 90° coincide with the GNA shift forward by more than 90° shift forward by 90° shift forward by less than 90° coincide with the GNA ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which motor used in Lathe machine? None of these D.C. shunt motor. D.C. cumulative compound motor. D.C . series motor. None of these D.C. shunt motor. D.C. cumulative compound motor. D.C . series motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC generator will not build up voltage if it has lost residual magnetism. due to wrong direction of rotation. any one of above. if field resistance is more than critical resistance. if it has lost residual magnetism. due to wrong direction of rotation. any one of above. if field resistance is more than critical resistance. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS