DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Lightning Magnetizing inrush current Switching over voltages Unbalanced protection Lightning Magnetizing inrush current Switching over voltages Unbalanced protection 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 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) Which type of back up protection is widely used for the protection of transmission lines? Breaker backup Control backup Remote backup Relay backup Breaker backup Control backup Remote backup Relay backup ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An IDMT relay provides A definite time characteristic for low values of the failt current and an inverse characteristic for high values of the fault current An inverse characteristic for low values of the fault current and a definite time characteristic for high values of the fault current A definite time cuttent characteristic An inverse time current characteristic A definite time characteristic for low values of the failt current and an inverse characteristic for high values of the fault current An inverse characteristic for low values of the fault current and a definite time characteristic for high values of the fault current A definite time cuttent characteristic An inverse time current characteristic 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 10 MVA 60 MVA 20 MVA 50 MVA 10 MVA 60 MVA 20 MVA 50 MVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA = Base kVA/%X
DGVCL Exam Paper (11-12-2011) The purpose of providing a choke in a tube light is To avoid radio interference To eliminate corona effect To improve the power factor To limit the current to an appropriate value To avoid radio interference To eliminate corona effect To improve the power factor To limit the current to an appropriate value ANSWER DOWNLOAD EXAMIANS APP
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