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) Which lightning stroke is most dangerous? Direct stroke on line conductor Direct stroke on ground wire Direct stoke on tower top Indirect stroke on conductor Direct stroke on line conductor Direct stroke on ground wire Direct stoke on tower top Indirect stroke on conductor ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The mutual inductance between two unity coupled coils of 9 H and 4 H is 36 H 2.2 H 6 H 13 H 36 H 2.2 H 6 H 13 H ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A Mho relay is a Voltage controlled over current relay Directional restrained over current relay Voltage restrained directional relay Directional restrained over voltage relay Voltage controlled over current relay Directional restrained over current relay Voltage restrained directional relay Directional restrained over voltage relay ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Leading power factor Depends on nature of load Unity power factor Lagging power factor Leading power factor Depends on nature of load Unity power factor Lagging power factor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Over excitation : leading currentUnder excitation : lagging currentNormal excitation : current with unity PF (in phase current)
DGVCL Exam Paper (11-12-2011) In carrier current protection, the purpose of the wave trap is for Tripping fault current Trapping high frequency waves entering into generator/transformer unit. Trapping power frequency waves All of these Tripping fault current Trapping high frequency waves entering into generator/transformer unit. Trapping power frequency waves All of these ANSWER DOWNLOAD EXAMIANS APP
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