Electrical Machines Which of the following windings are necessary in case of all dc machines? closed winding open type winding wave winding lap winding closed winding open type winding wave winding lap winding ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a transformer is loaded, the secondary terminal voltage drops. That means power factor is zero. leading. lagging. unity. zero. leading. lagging. unity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up 230 V when driven in clockwise direction. In case it is driven in anti clockwise direction, other things remaining unchanged, then the voltage build up is not possible some what less than 230 V some what more than 230 V 230 V not possible some what less than 230 V some what more than 230 V 230 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : For a level compounded dc generator to run at constant voltage, the series field mmf must effectively compensate 1. armature reaction mmf 2.armature resistance drop 3. brush contact voltage drop Which of these statements is/are correct ? 2 alone 1, 2 and 3 1 and 3 1 and 2 2 alone 1, 2 and 3 1 and 3 1 and 2 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% 82.5% 67.5% 78.5% 72.5% 82.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flashing the field of DC generator means 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. increasing flux density by adding extra turns of winding. ANSWER DOWNLOAD EXAMIANS APP
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