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 More than 90% Less than 90% 80 % 90 % More than 90% Less than 90% 80 % 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) The best location of the power factor correction equipment to be installed in the transmission line is at Any place The sending end The receiving end Middle of the line Any place The sending end The receiving end Middle of the line ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) If a 5 A fuse is blown frequently in a house lighting circuit, it is required to Insert a fuse of higher current rating Insert a fuse of higher voltage rating Check the load Reduce the load Insert a fuse of higher current rating Insert a fuse of higher voltage rating Check the load Reduce the load ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Unbalanced protection Switching over voltages Lightning Magnetizing inrush current Unbalanced protection Switching over voltages Lightning Magnetizing inrush current ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Initial inrush of magnetizing currents have high component of even and odd harmonics.2nd - 63%3rd -26.8%4th- 5.1%5th- 4.1%6th- 3.77th-2.4
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 secondary ciruits It is safe to human beings It protects the primary ciruits It avoids core saturation and high voltage induction It protects the secondary ciruits It is safe to human beings It protects the primary ciruits ANSWER DOWNLOAD EXAMIANS APP
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