DGVCL Exam Paper (11-12-2011) The purpose of interpoles in DC machines is to nullify Both the cross-magnetizing mmf and the reactance voltage The demagnetizing effect of armature mmf The reactance voltage The cross-magnetizing effect of armature mmf Both the cross-magnetizing mmf and the reactance voltage The demagnetizing effect of armature mmf The reactance voltage The cross-magnetizing effect of armature mmf ANSWER EXPLANATION DOWNLOAD EXAMIANS APP interpoles is widely use to improve commutationplace between main poles fitted to yokefunctions:to neutralize armature mmf in commutating zoneto produce some flux in commutating zone
DGVCL Exam Paper (11-12-2011) If the voltage at the two ends of a line are 132 kV, and its reactance is 40 Ω, the stability limit of the line is 251.5 MW 500 MW 435.6 MW 217.8 MW 251.5 MW 500 MW 435.6 MW 217.8 MW ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The transient stability of a power system can be improved by Phase shifting transformer Excitation control Single pole switching of circuit breakers Increasing the turbine valve opening Phase shifting transformer Excitation control Single pole switching of circuit breakers Increasing the turbine valve opening 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 20 MVA 60 MVA 10 MVA 50 MVA 20 MVA 60 MVA 10 MVA 50 MVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA = Base kVA/%X
DGVCL Exam Paper (11-12-2011) A Mho relay is a Voltage restrained directional relay Voltage controlled over current relay Directional restrained over current relay Directional restrained over voltage relay Voltage restrained directional relay Voltage controlled over current relay Directional restrained over current relay Directional restrained over voltage relay ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In a series RLC circuit at resonance Current is minimum and power factor is 0.5 Current is maximum and power factor is 0.5 Current is minimum and power factor is unity Current is maximum and power factor is unity Current is minimum and power factor is 0.5 Current is maximum and power factor is 0.5 Current is minimum and power factor is unity Current is maximum and power factor is unity ANSWER DOWNLOAD EXAMIANS APP
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