Electrical Machines Flux density under trailing pole tips in case of generator will increase either increase or decrease None of these decrease increase either increase or decrease None of these decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The compensating winding in a DC machine is located on pole shoes for avoiding the flashover at the commutator. is located in armature slots for compensation of the armature reaction. is located on pole shoes to avoid the sparking at the brushes. is located on commutating poles for improving commutation. is located on pole shoes for avoiding the flashover at the commutator. is located in armature slots for compensation of the armature reaction. is located on pole shoes to avoid the sparking at the brushes. is located on commutating poles for improving commutation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 67.5% 72.5% 78.5% 82.5% 67.5% 72.5% 78.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
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 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. Heavy sparking at the first stud of starting resistance steps. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum power developed by a synchronous motor depends on supply voltage and excitation supply voltage, load angle and excitation supply voltage and load angle excitation and load angle supply voltage and excitation supply voltage, load angle and excitation supply voltage and load angle excitation and load angle ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by fixing the brush axis inline with the pole axis. increasing field excitation. shifting the brush axis from GNA to MNA. compensating winding and commutating poles. fixing the brush axis inline with the pole axis. increasing field excitation. shifting the brush axis from GNA to MNA. compensating winding and commutating poles. ANSWER DOWNLOAD EXAMIANS APP
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