DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Lightning Unbalanced protection Magnetizing inrush current Switching over voltages Lightning Unbalanced protection Magnetizing inrush current Switching over voltages 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) If the fault current is 2000 A, the relay plug setting is 50% and the CT ratio is 400/5, the plug setting multiple will be 25 10 50 15 25 10 50 15 ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Reactance relay is used to protect against Both phase and earth faults Over voltage faults Earth faults only Phase faults only Both phase and earth faults Over voltage faults Earth faults only Phase faults only 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 50 MVA 60 MVA 20 MVA 10 MVA 50 MVA 60 MVA 20 MVA 10 MVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA = Base kVA/%X
DGVCL Exam Paper (11-12-2011) In a power plant, a reserve generating capacity which is not in service but is in operation is known as Hot reserve Spinning reserve Cold reserve Firm power Hot reserve Spinning reserve Cold reserve Firm power ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Hysteresis in an instrument means The inaccuracy due to change in temperature The reliability of the instrument The change in the same reading when the input is first increased and then decreased The repeatability of the instrument The inaccuracy due to change in temperature The reliability of the instrument The change in the same reading when the input is first increased and then decreased The repeatability of the instrument ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS