Electrical Machines A large series motor is never started without some mechanical load on it because otherwise it will draw too much current. produce sparking at brushes. develop excessive speed and damage itself. open fuse or circuit breaker. draw too much current. produce sparking at brushes. develop excessive speed and damage itself. open fuse or circuit breaker. 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%. 82.5% 67.5% 78.5% 72.5% 82.5% 67.5% 78.5% 72.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flashing the field of DC generator means increasing flux density by adding extra turns of winding. making the magnetic losses forces parallel. neutralising residual magnetism. creating residual magnetism by a DC source. increasing flux density by adding extra turns of winding. making the magnetic losses forces parallel. neutralising residual magnetism. creating residual magnetism by a DC source. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In salient pole synchronous machine, the reluctance power varies as cosδ sinδ cos2δ sin2δ cosδ sinδ cos2δ sin2δ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which 1 - Φ motor does operate at high power factor? Split phase. Capacitor run. Shaded pole. Capacitor start. Split phase. Capacitor run. Shaded pole. Capacitor start. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is not a part of transformer? Commutator. Tap changer. Conservator tank. Radiator. Commutator. Tap changer. Conservator tank. Radiator. ANSWER DOWNLOAD EXAMIANS APP
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