Electrical Machines The sparking at the the brushes, in a DC machines is due to high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous motor the torque is proportional to Power P 1/P 1/P² P² Power P 1/P 1/P² P² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA 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 speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 960 RPM 940 RPM 970 RPM 920 RPM 960 RPM 940 RPM 970 RPM 920 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power flow of a dc motor, with respect to a DC generator is modified. none of these. increased. reversed. modified. none of these. increased. reversed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The wound rotor type IM is used for____________ speed operation. minimum. variable. constant. maximum. minimum. variable. constant. maximum. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage of a DC motor is 230 V, then back emf, for maximum power developed is 230 V. 460 V. 200 V. 115 V. 230 V. 460 V. 200 V. 115 V. ANSWER DOWNLOAD EXAMIANS APP
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