DGVCL Exam Paper (11-12-2011) The form factor in AC means the ration of 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 R.M.S. value to average value ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A 3 phase, 6 pole induction motor operates on 440 V, 50 Hz, supply. If the actual speed of the motor is 960 rpm the slip will be 0.4 % 5 % 6 % 4 % 0.4 % 5 % 6 % 4 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ns = 120f/PSlip=(Ns-Nr)/NsNs = 1000 and Nr = 960 from equation of slip, S = (1000-960)/1000S = 0.04 or 4%
DGVCL Exam Paper (11-12-2011) Buchholz relay causes Tripping for both major and minor faults Tripping for major faults and alarm for minor faults Alarm for both major and minor faults Tripping for minor faults and alarm for major faults Tripping for both major and minor faults Tripping for major faults and alarm for minor faults Alarm 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) A Mho relay is a Voltage restrained directional relay Directional restrained over current relay Directional restrained over voltage relay Voltage controlled over current relay Voltage restrained directional relay Directional restrained over current relay Directional restrained over voltage relay Voltage controlled over current relay ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) First zone distance relay protects the transmission line section upto 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 Its full length 25 % of its full length 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 90 % More than 90% Less than 90% 80 % 90 % More than 90% Less than 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
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