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 Peak value to average value R.M.S. value to peak value R.M.S. value to average value Peak value to r.m.s value Peak value to average value R.M.S. value to peak value ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) If the percentage reactance of the system upto the point of fault is 20% and the base kVA is 10,000 the short ciruit kVA is 20 MVA 50 MVA 60 MVA 10 MVA 20 MVA 50 MVA 60 MVA 10 MVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA = Base kVA/%X
DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Magnetizing inrush current Switching over voltages Unbalanced protection Lightning Magnetizing inrush current Switching over voltages Unbalanced protection Lightning 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) 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 % Less than 90% 90 % More than 90% 80 % Less than 90% 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) What happens to the contents of RAM (Random Access Memory) when the power of the computer is turned off? Content is transferred to other memory Content remains intact Content gets corrupted Content is lost Content is transferred to other memory Content remains intact Content gets corrupted Content is lost 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 Middle of the line Any place The receiving end The sending end Middle of the line Any place The receiving end The sending end ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS