Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 2 at 90°C. 1 at 90°C. 3 at 90°C. 0.5 at 90°C. 2 at 90°C. 1 at 90°C. 3 at 90°C. 0.5 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when commissioned after a major repair of the field system, failed to build Up voltage. It was because field system lost residual magnetism there was a break in the armature circuit field winding was wrongly connected field resistance was higher than critical resistance field system lost residual magnetism there was a break in the armature circuit field winding was wrongly connected field resistance was higher than critical resistance ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following voltage regulator is preferred for providing large values of load current? Transistor series regulator. Zener diode shunt regulator. Transistor shunt regulator. None of these Transistor series regulator. Zener diode shunt regulator. Transistor shunt regulator. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous generator a synchronous dead load (lamp, furnaces etc) has no ____________ hence it has no natural frequency of oscillation. mechanical rotatory system. damping torque. synchronizing power co efficient. restoring torque. mechanical rotatory system. damping torque. synchronizing power co efficient. restoring torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, alternator has generated emf per phase of 230 V with 10% 3rd harmonic and 6% 5th harmonic content. Calculate rms line voltage for star connection. 230.2 V. 50 V. 100 V. 399 V. 230.2 V. 50 V. 100 V. 399 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous generator, inverted V curve is drawn between field current on X-axis and armature current on Y-axis field current on Y-axis and armature current on X-axis field current on X-axis and power factor on Y-axis field current on Y-axis and power factor on X-axis field current on X-axis and armature current on Y-axis field current on Y-axis and armature current on X-axis field current on X-axis and power factor on Y-axis field current on Y-axis and power factor on X-axis ANSWER DOWNLOAD EXAMIANS APP
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