DGVCL Exam Paper (11-12-2011) If the dielectric strength of the medium between the contacts builds up more rapidly than the restriking voltage the arc will Restrike Decrease in size Extinguish Increase in size Restrike Decrease in size Extinguish Increase in size ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The circuit breaker generally used in railway traction is Air break CB Vacuum CB Minimum Oil CB Bulk Oil CB Air break CB Vacuum CB Minimum Oil CB Bulk Oil CB ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In carrier current protection, the purpose of the wave trap is for Trapping high frequency waves entering into generator/transformer unit. All of these Tripping fault current Trapping power frequency waves Trapping high frequency waves entering into generator/transformer unit. All of these Tripping fault current Trapping power frequency waves ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) If a 5 A fuse is blown frequently in a house lighting circuit, it is required to Reduce the load Insert a fuse of higher voltage rating Check the load Insert a fuse of higher current rating Reduce the load Insert a fuse of higher voltage rating Check the load Insert a fuse of higher current rating ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Lagging power factor Depends on nature of load Unity power factor Leading power factor Lagging power factor Depends on nature of load Unity power factor 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) 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 90 % More than 90% 80 % Less than 90% 90 % More than 90% 80 % 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
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