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. 0.443. 0.573. 0.649. 0.512. 0.443. 0.573. 0.649. 0.512. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In field flux method speed control of DC Motor is constant torque drive below the base speed. constant hp drive below the base speed. constant torque drive above the base speed. constant power drive above base speed. constant torque drive below the base speed. constant hp drive below the base speed. constant torque drive above the base speed. constant power drive above base speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous motor, the damper winding is generally used to reduce noise level only. prevent hunting and provide the starting torque. provide starting torque only. reduce the eddy currents. reduce noise level only. prevent hunting and provide the starting torque. provide starting torque only. reduce the eddy currents. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Transformer oil is used as an insulator. both A and B. inert medium. a coolant. an insulator. both A and B. inert medium. a coolant. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The demagnetising component of armature reaction in a DC generator reduces generator emf. increases armature speed. reduces inter poles flux density. results in sparking trouble. reduces generator emf. increases armature speed. reduces inter poles flux density. results in sparking trouble. 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 less than 90° coincide with the GNA shift forward by 90° shift forward by more than 90° shift forward by less than 90° coincide with the GNA shift forward by 90° ANSWER DOWNLOAD EXAMIANS APP
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