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 % 80 % Less than 90% More than 90% 90 % 80 % Less than 90% More 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) A fixed step by step procedure for finding the solution of a problem on computer is called Hardware Software Logic Algorithm Hardware Software Logic Algorithm ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Buchholz relay causes Tripping for both major and minor faults Tripping for minor faults and alarm for major faults Alarm for both major and minor faults Tripping for major faults and alarm for minor faults Tripping for both major and minor faults Tripping for minor faults and alarm for major faults Alarm for both major and minor faults Tripping for major faults and alarm for minor faults ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Bulk power transmission over long HVDC lines are preferred on account of No harmonic problems Minimum line power losses Simple protection Low cost of HVDC terminals No harmonic problems Minimum line power losses Simple protection Low cost of HVDC terminals ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Under operating conditions, the secondary of a current transformer is always short ciruited because It avoids core saturation and high voltage induction It protects the primary ciruits It is safe to human beings It protects the secondary ciruits It avoids core saturation and high voltage induction It protects the primary ciruits It is safe to human beings It protects the secondary ciruits ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) If the dielectric strength of the medium between the contacts builds up more rapidly than the restriking voltage the arc will Decrease in size Restrike Increase in size Extinguish Decrease in size Restrike Increase in size Extinguish ANSWER DOWNLOAD EXAMIANS APP
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