Electrical Machines A 230 V, 50 Hz, 4 pole single phase induction motor is rotating in the clockwise ( forward ) direction at a speed of 1425 rpm. If the rotor resistance at standstill is 7.8 Ω. Then the effective rotor resistance in the backward branch of the equivalent circuit will be 4 Ω. 8 Ω. 10 Ω. 2 Ω. 4 Ω. 8 Ω. 10 Ω. 2 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Type of single phase motor having highest power factor at full load is capacitor run. shaded pole type. split phase. capacitor start. capacitor run. shaded pole type. split phase. capacitor start. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines No load test of 3-phase induction motor gives which of the following? constant loss both A and B None of these variable loss constant loss both A and B None of these variable loss 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%. 78.5% 72.5% 67.5% 82.5% 78.5% 72.5% 67.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC motor, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will improve and the speed falls. deteriorate and the speed falls. deteriorate and the speed rises. improve and the speed rises. improve and the speed falls. deteriorate and the speed falls. deteriorate and the speed rises. improve and the speed rises. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC Motor 3 point starter is used to provide overload protection. all of above. provide protection against Low-Voltage. limit the starting current to a safer value. provide overload protection. all of above. provide protection against Low-Voltage. limit the starting current to a safer value. ANSWER DOWNLOAD EXAMIANS APP
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