Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Heavy sparking at the first stud of starting resistance steps. None of these. Heavy sparking at brushes. Both of above. Heavy sparking at the first stud of starting resistance steps. None of these. Heavy sparking at brushes. Both of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flashing the field of DC generator means making the magnetic losses forces parallel. neutralising residual magnetism. increasing flux density by adding extra turns of winding. creating residual magnetism by a DC source. making the magnetic losses forces parallel. neutralising residual magnetism. increasing flux density by adding extra turns of winding. creating residual magnetism by a DC source. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What type of dielectric material is used in capacitors used for fans and for power factor correction? Oil impregnated paper. Glass. Mica. Vacuum. Oil impregnated paper. Glass. Mica. Vacuum. ANSWER DOWNLOAD EXAMIANS APP
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. 0.512. 0.443. 0.649. 0.573. 0.512. 0.443. 0.649. 0.573. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by increasing field excitation. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. fixing the brush axis inline with the pole axis. increasing field excitation. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. fixing the brush axis inline with the pole axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in dc motor results increase in speed. short circuit. decrease in speed. open circuit. increase in speed. short circuit. decrease in speed. open circuit. ANSWER DOWNLOAD EXAMIANS APP