DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Leading power factor Unity power factor Depends on nature of load Lagging power factor Leading power factor Unity power factor Depends on nature of load Lagging power factor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Over excitation : leading currentUnder excitation : lagging currentNormal excitation : current with unity PF (in phase current)
DGVCL Exam Paper (11-12-2011) An AC series circuit has R = 6 Ω, XL = 20 Ω and Xc = 12 Ω. The ciruit power factor will be 0.6 lagging 0.6 leading 0.5 leading 0.8 lagging 0.6 lagging 0.6 leading 0.5 leading 0.8 lagging ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Under operating conditions, the secondary of a current transformer is always short ciruited because It avoids core saturation and high voltage induction It is safe to human beings It protects the secondary ciruits It protects the primary ciruits It avoids core saturation and high voltage induction It is safe to human beings It protects the secondary ciruits It protects the primary ciruits ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) At time t= 0+ , with zero initial condition, which of the following acts as a short circuit? Conductor Resistor Capacitor Voltage source Conductor Resistor Capacitor Voltage source ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Fot fast load flow calculations, the best method is Approximate method De-coupled method Gauss-Siedal Newton-Raphson Approximate method De-coupled method Gauss-Siedal Newton-Raphson ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Unbalanced protection Lightning Magnetizing inrush current Switching over voltages Unbalanced protection Lightning Magnetizing inrush current Switching over voltages ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Initial inrush of magnetizing currents have high component of even and odd harmonics.2nd - 63%3rd -26.8%4th- 5.1%5th- 4.1%6th- 3.77th-2.4