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% More than 90% 90 % 80 % Less than 90% More 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) 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 6 % 0.4 % 5 % 4 % 6 % 0.4 % 5 % 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) First zone distance relay protects the transmission line section upto 50 % of its full length Its full length 80 % of its full length 25 % of its full length 50 % of its full length Its full length 80 % of its full length 25 % of its full length ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The main criterion for the design of a distributor is Radio interference Temperature rise Corona loss Voltage drop Radio interference Temperature rise Corona loss Voltage drop ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A fixed step by step procedure for finding the solution of a problem on computer is called Algorithm Software Hardware Logic Algorithm Software Hardware Logic ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A Mho relay is a Voltage controlled over current relay Directional restrained over current relay Voltage restrained directional relay Directional restrained over voltage relay Voltage controlled over current relay Directional restrained over current relay Voltage restrained directional relay Directional restrained over voltage relay ANSWER DOWNLOAD EXAMIANS APP
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