DGVCL Exam Paper (11-12-2011) If the voltage at the two ends of a line are 132 kV, and its reactance is 40 Ω, the stability limit of the line is 251.5 MW 217.8 MW 435.6 MW 500 MW 251.5 MW 217.8 MW 435.6 MW 500 MW ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Rated making capacity of a ciruit breaker is equal to 1.11 X rated symmetrical breaking capacity Rated symmetrical breaking capacity 2.55 X rated symmetrical breaking capacity √2 X rated symmetrical breaking capacity 1.11 X rated symmetrical breaking capacity Rated symmetrical breaking capacity 2.55 X rated symmetrical breaking capacity √2 X rated symmetrical breaking capacity ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which lightning stroke is most dangerous? Direct stroke on ground wire Direct stoke on tower top Indirect stroke on conductor Direct stroke on line conductor Direct stroke on ground wire Direct stoke on tower top Indirect stroke on conductor Direct stroke on line conductor ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The purpose of providing a choke in a tube light is To improve the power factor To limit the current to an appropriate value To avoid radio interference To eliminate corona effect To improve the power factor To limit the current to an appropriate value To avoid radio interference To eliminate corona effect ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The efficiency of a transformer at full load, 0.8 p.f. lag is 90%. Its efficiency at full load, 0.8 p.f. lead will be 80 % 90 % More than 90% Less than 90% 80 % 90 % More than 90% Less than 90% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Efficiency= output power/input powerefficiency = (v*i*cosφ)/((v*i*cosφ)+(x² Pc)+(Pi)) x=fractional part of full load
DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Magnetizing inrush current Lightning Unbalanced protection Switching over voltages Magnetizing inrush current Lightning Unbalanced protection 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