Electrical Machines Transformer oil is used as an insulator. a coolant. inert medium. both A and B. an insulator. a coolant. inert medium. both A and B. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by 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. fixing the brush axis inline with the pole axis. increasing field excitation. shifting the brush axis from GNA to MNA. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Tertiary winding in a transformer is mostly star connected. zig - zag delta connected. zig - zag star connected. delta connected. star connected. zig - zag delta connected. zig - zag star connected. delta connected. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2 A armature current at no-load, when the armature current is changed to 20 A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 1130 r.p.m. 4575.4 r.p.m. none of above. 1037.5 r.p.m. 1130 r.p.m. 4575.4 r.p.m. none of above. 1037.5 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following DC Motor uses 4-point starter? DC shunt motor with armature resistance. DC compound motor. DC series motor. DC shunt motor with field weaking control. DC shunt motor with armature resistance. DC compound motor. DC series motor. DC shunt motor with field weaking control. 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% 78.5% 67.5% 72.5% 82.5% 78.5% 67.5% 72.5% ANSWER DOWNLOAD EXAMIANS APP
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