DGVCL Exam Paper (11-12-2011) Buchholz relay causes Tripping for major faults and alarm for minor faults Alarm for both major and minor faults Tripping for both major and minor faults Tripping for minor faults and alarm for major faults Tripping for major faults and alarm for minor faults Alarm for both major and minor faults Tripping for both major and minor faults Tripping for minor faults and alarm for major faults ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The insulation coordination for UHV lines (above 500 kV) is done based on Switching surges Voltage level of the line Lightning surges Lightning and switching surges Switching surges Voltage level of the line Lightning surges Lightning and switching surges 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 Less than 90% 80 % More than 90% 90 % Less than 90% 80 % More than 90% 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) Which type of back up protection is widely used for the protection of transmission lines? Control backup Breaker backup Relay backup Remote backup Control backup Breaker backup Relay backup Remote backup ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The form factor in AC means the ration of R.M.S. value to peak value R.M.S. value to average value Peak value to r.m.s value Peak value to average value R.M.S. value to peak value R.M.S. value to average value Peak value to r.m.s value Peak value to average value ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) First zone distance relay protects the transmission line section upto Its full length 25 % of its full length 80 % of its full length 50 % of its full length Its full length 25 % of its full length 80 % of its full length 50 % of its full length ANSWER DOWNLOAD EXAMIANS APP
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