Electrical Machines If the excitation is reduced, the power factor is lagging power factor unity power factor None of these leading power factor lagging power factor unity power factor None of these leading power factor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 12 pole triplex lap wound DC armature, each conductor can carry current of 100 A. The rated current of this armature is 1200 A. 3600 A. 2400 A. 600 A. 1200 A. 3600 A. 2400 A. 600 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A series generator is connected in series to a feeder having 0.5Ω resistance to boost the voltage. The induced voltage is given by Eg = 0.6Ia, Ra = 0.2Ω and Rs = 0.3Ω. Find the voltage boosted by the generator, when delivering 400 Amp? 30 V. 90 V. 60 V. 40 V. 30 V. 90 V. 60 V. 40 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4-pole DC generator runs at 1500 rpm. The frequency of current in the armature winding is: 50 Hz. 100 Hz. Zero Hz. 25 Hz. 50 Hz. 100 Hz. Zero Hz. 25 Hz. 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% 82.5% 72.5% 67.5% 78.5% 82.5% 72.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited DC generator, running at rated speed, has 6 volts across its armature terminals with no field current. When field winding is excited with one ampere, the voltage builds up to 250 V at no load. In case field current is reduced to zero, with the speed remaining unaltered, the armature terminal voltage would be 6 V more than 6 V less than 6 V zero 6 V more than 6 V less than 6 V zero ANSWER DOWNLOAD EXAMIANS APP
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