DGVCL Exam Paper (11-12-2011) The transient stability of a power system can be improved by Increasing the turbine valve opening Single pole switching of circuit breakers Excitation control Phase shifting transformer Increasing the turbine valve opening Single pole switching of circuit breakers Excitation control Phase shifting transformer ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In a series RLC circuit at resonance Current is minimum and power factor is unity Current is minimum and power factor is 0.5 Current is maximum and power factor is unity Current is maximum and power factor is 0.5 Current is minimum and power factor is unity Current is minimum and power factor is 0.5 Current is maximum and power factor is unity Current is maximum and power factor is 0.5 ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The form factor in AC means the ration of R.M.S. value to average value Peak value to r.m.s value R.M.S. value to peak value Peak value to average value R.M.S. value to average value Peak value to r.m.s value R.M.S. value to peak value Peak value to average value ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which of the following power distribution system gives better reliabity ? Radial system None of these Ring main system DC 3 wire system Radial system None of these Ring main system DC 3 wire system 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) Buchholz relay causes Tripping for minor faults and alarm for major faults Alarm for both major and minor faults Tripping for both major and minor faults Tripping for major faults and alarm for minor faults Tripping for minor faults and alarm for major faults Alarm for both major and minor faults Tripping for both major and minor faults Tripping for major faults and alarm for minor faults ANSWER DOWNLOAD EXAMIANS APP
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