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 10 MVA 60 MVA 50 MVA 20 MVA 10 MVA 60 MVA 50 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 Lightning Switching over voltages Unbalanced protection Magnetizing inrush current Lightning Switching over voltages Unbalanced protection 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) Ybus used in power flow studies and Zbus used in short circuit studies Have no inter relation Are transpose of each other Are inverse of each other Are the same Have no inter relation Are transpose of each other Are inverse of each other Are the same 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? Remote backup Control backup Relay backup Breaker backup Remote backup Control backup Relay backup Breaker backup ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The positive and negative sequence impedance of a transmission line are Different Equal Zero Infinite Different Equal Zero Infinite ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Reactance relay is used to protect against Over voltage faults Earth faults only Both phase and earth faults Phase faults only Over voltage faults Earth faults only Both phase and earth faults Phase faults only ANSWER DOWNLOAD EXAMIANS APP
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