DGVCL Exam Paper (11-12-2011) In carrier current protection, the purpose of the wave trap is for Trapping power frequency waves All of these Tripping fault current Trapping high frequency waves entering into generator/transformer unit. Trapping power frequency waves All of these Tripping fault current Trapping high frequency waves entering into generator/transformer unit. 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 % More than 90% 90 % Less than 90% 80 % More than 90% 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) The bus bar zone faults are generally Double line to ground faults Phase to phase faults Three phase short ciruits Single line to ground faults Double line to ground faults Phase to phase faults Three phase short ciruits Single line to ground faults ANSWER DOWNLOAD EXAMIANS APP
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 500 MW 251.5 MW 217.8 MW 435.6 MW 500 MW 251.5 MW 217.8 MW 435.6 MW ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The mutual inductance between two unity coupled coils of 9 H and 4 H is 13 H 36 H 6 H 2.2 H 13 H 36 H 6 H 2.2 H ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which lightning stroke is most dangerous? Direct stroke on ground wire Direct stroke on line conductor Direct stoke on tower top Indirect stroke on conductor Direct stroke on ground wire Direct stroke on line conductor Direct stoke on tower top Indirect stroke on conductor ANSWER DOWNLOAD EXAMIANS APP
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