DGVCL Exam Paper (11-12-2011) Which type of back up protection is widely used for the protection of transmission lines? Control backup Relay backup Breaker backup Remote backup Control backup Relay backup Breaker backup Remote backup ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The circuit breaker generally used in railway traction is Bulk Oil CB Vacuum CB Minimum Oil CB Air break CB Bulk Oil CB Vacuum CB Minimum Oil CB Air break CB ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A Mho relay is a Directional restrained over current relay Voltage restrained directional relay Voltage controlled over current relay Directional restrained over voltage relay Directional restrained over current relay Voltage restrained directional relay Voltage controlled over current relay Directional restrained over voltage relay ANSWER DOWNLOAD EXAMIANS APP
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) DC series motors are best suited for traction work because Its torque is proportional to the square of the armature current and speed is directional proporational to torque Its torque is proportional to the square of the armature current and speed is inversely proportional to torque Torque and speed are inversely proportional to the square of the armature current Torque and speed are proportional to the square of the armature current Its torque is proportional to the square of the armature current and speed is directional proporational to torque Its torque is proportional to the square of the armature current and speed is inversely proportional to torque Torque and speed are inversely proportional to the square of the armature current Torque and speed are proportional to the square of the armature current ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Torque in d.c motor = k* φ * IaIn series motor φ α IaTα I²N α 1/φN α 1/T
DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Lagging power factor Leading power factor Unity power factor Depends on nature of load Lagging power factor Leading power factor Unity 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)
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