Electrical Machines A transformer has maximum efficiency at 3/4 load. The ratio of iron loss and full load copper loss is 9/16. 16/9. 4/3. 3/4. 9/16. 16/9. 4/3. 3/4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable acidity level of power transformer insulating oil is generally taken as 0.5 mg of KOH / gm. 0.3 mg of KOH / gm. 1 mg of KOH / gm. 2 mg of KOH / gm. 0.5 mg of KOH / gm. 0.3 mg of KOH / gm. 1 mg of KOH / gm. 2 mg of KOH / gm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If in a sub – station there is one 132 / 33 kV transformer whose secondary is connected with primary of one 33 / 11 kV transformer, the total transformation ratio of the sub – station will be, 12. 4. 3. 7. 12. 4. 3. 7. 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 less than 6 V zero 6 V more than 6 V less than 6 V zero 6 V more than 6 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines During hunting of a synchronous motor damper bar develops torque. negative phase sequence currents are generated. field excitation increases. harmonic are developed in the armature circuit. damper bar develops torque. negative phase sequence currents are generated. field excitation increases. harmonic are developed in the armature circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following statement is correct, if short circuit ratio is high? Good voltage regulation None of these Low short circuit current High voltage regulation Good voltage regulation None of these Low short circuit current High voltage regulation ANSWER DOWNLOAD EXAMIANS APP
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