DGVCL Exam Paper (11-12-2011) Hysteresis in an instrument means The repeatability of the instrument The inaccuracy due to change in temperature The change in the same reading when the input is first increased and then decreased The reliability of the instrument The repeatability of the instrument The inaccuracy due to change in temperature The change in the same reading when the input is first increased and then decreased The reliability of the instrument ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) If the excitation of a synchronous generator fails, it acts as a Synchronous generator Induction generator Synchronous motor Induction motor Synchronous generator Induction generator Synchronous motor Induction motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP if excitation of synchronous generator fails, operate as induction motor
DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Unity power factor Leading power factor Lagging power factor Depends on nature of load Unity power factor Leading power factor Lagging power factor Depends on nature of load 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) The purpose of interpoles in DC machines is to nullify The demagnetizing effect of armature mmf The cross-magnetizing effect of armature mmf The reactance voltage Both the cross-magnetizing mmf and the reactance voltage The demagnetizing effect of armature mmf The cross-magnetizing effect of armature mmf The reactance voltage Both the cross-magnetizing mmf and the reactance voltage 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) Reactance relay is used to protect against Over voltage faults Both phase and earth faults Phase faults only Earth faults only Over voltage faults Both phase and earth faults Phase faults only Earth faults only ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An AC series circuit has R = 6 Ω, XL = 20 Ω and Xc = 12 Ω. The ciruit power factor will be 0.5 leading 0.6 lagging 0.6 leading 0.8 lagging 0.5 leading 0.6 lagging 0.6 leading 0.8 lagging ANSWER DOWNLOAD EXAMIANS APP
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