Electrical Machines 1 KVA, 230 V, 50 Hz, single phase transformer has an eddy current loss of 30 watts. The eddy current loss when the transformer is excited by a dc source of same voltage will be more than 30 W less than 30 W 30 W zero watt more than 30 W less than 30 W 30 W zero watt 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%. 72.5% 67.5% 78.5% 82.5% 72.5% 67.5% 78.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In alternator, the rotary part is armature. none of these. core. magnetic field poles. armature. none of these. core. magnetic field poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush They are self lubricating in nature All of these In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush They are self lubricating in nature All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The effect of ------------------ on main field flux is armature reaction? armature flux armature mmf armature current All of these armature flux armature mmf armature current All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by s2. sf / 2. f / s. sf. s2. sf / 2. f / s. sf. ANSWER DOWNLOAD EXAMIANS APP
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