DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Magnetizing inrush current Switching over voltages Lightning Unbalanced protection Magnetizing inrush current Switching over voltages Lightning 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) 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 60 MVA 10 MVA 20 MVA 50 MVA 60 MVA 10 MVA 20 MVA 50 MVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA = Base kVA/%X
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 50 15 10 25 50 15 10 ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In a series RLC circuit at resonance Current is maximum and power factor is unity Current is maximum and power factor is 0.5 Current is minimum and power factor is 0.5 Current is minimum and power factor is unity Current is maximum and power factor is unity Current is maximum and power factor is 0.5 Current is minimum and power factor is 0.5 Current is minimum and power factor is unity ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Transposition of transmission line is done to Reduce skin effect Balance line voltage drop Reduce line loss Reduce corona Reduce skin effect Balance line voltage drop Reduce line loss Reduce corona ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which motor is used to start heavy loads? Series motor Cumulatively compounded motor Differentially compounded motor Shunt motor Series motor Cumulatively compounded motor Differentially compounded motor Shunt motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Torque in d.c motor = k* φ * IaIn series motor φ α IaTα I²starting torque of dc series motor is high
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