DGVCL Exam Paper (11-12-2011) Which type of back up protection is widely used for the protection of transmission lines? Relay backup Remote backup Control backup Breaker backup Relay backup Remote backup Control backup Breaker backup ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Permittivity is expressed in terms of N/m Weber /m Farad/m farad/sq. m. N/m Weber /m Farad/m farad/sq. m. ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) If the percentage reactance of the system upto the point of fault is 20% and the base kVA is 10,000 the short ciruit kVA is 10 MVA 50 MVA 20 MVA 60 MVA 10 MVA 50 MVA 20 MVA 60 MVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA = Base kVA/%X
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 More than 90% Less than 90% 90 % 80 % More than 90% Less than 90% 90 % 80 % 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) Transposition of transmission line is done to Reduce line loss Reduce skin effect Reduce corona Balance line voltage drop Reduce line loss Reduce skin effect Reduce corona Balance line voltage drop ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The purpose of providing a choke in a tube light is To avoid radio interference To limit the current to an appropriate value To improve the power factor To eliminate corona effect To avoid radio interference To limit the current to an appropriate value To improve the power factor To eliminate corona effect ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS