DGVCL Exam Paper (11-12-2011) First zone distance relay protects the transmission line section upto 80 % of its full length Its full length 25 % of its full length 50 % of its full length 80 % of its full length Its full length 25 % of its full length 50 % of its full length ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Reactance relay is used to protect against Earth faults only Over voltage faults Both phase and earth faults Phase faults only Earth faults only Over voltage faults Both phase and earth faults Phase faults only ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Magnetizing inrush current Lightning Switching over voltages Unbalanced protection Magnetizing inrush current Lightning Switching over voltages Unbalanced protection 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
DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Lagging power factor Unity power factor Depends on nature of load Leading power factor Lagging power factor Unity power factor Depends on nature of load Leading 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) Transposition of transmission line is done to Balance line voltage drop Reduce line loss Reduce corona Reduce skin effect Balance line voltage drop Reduce line loss Reduce corona Reduce skin effect 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 Capacitor Voltage source Resistor Conductor Capacitor Voltage source Resistor ANSWER DOWNLOAD EXAMIANS APP