DGVCL Exam Paper (11-12-2011) The transient stability of a power system can be improved by Phase shifting transformer Excitation control Increasing the turbine valve opening Single pole switching of circuit breakers Phase shifting transformer Excitation control Increasing the turbine valve opening Single pole switching of circuit breakers ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Switching over voltages Lightning Magnetizing inrush current Unbalanced protection Switching over voltages Lightning Magnetizing inrush current 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) The insulation coordination for UHV lines (above 500 kV) is done based on Switching surges Lightning and switching surges Voltage level of the line Lightning surges Switching surges Lightning and switching surges Voltage level of the line Lightning surges ANSWER DOWNLOAD EXAMIANS APP
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 leading 0.8 lagging 0.5 leading 0.6 lagging 0.6 leading 0.8 lagging 0.5 leading 0.6 lagging ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An IDMT relay provides An inverse time current characteristic An inverse characteristic for low values of the fault current and a definite time characteristic for high values of the fault current A definite time cuttent characteristic A definite time characteristic for low values of the failt current and an inverse characteristic for high values of the fault current An inverse time current characteristic An inverse characteristic for low values of the fault current and a definite time characteristic for high values of the fault current A definite time cuttent characteristic A definite time characteristic for low values of the failt current and an inverse characteristic for high values of the fault current ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) What type of insulator is used if the direction of the transmission line is to be changed? Pin type Suspebsion type Strain type Shakle type Pin type Suspebsion type Strain type Shakle type ANSWER DOWNLOAD EXAMIANS APP