DGVCL Exam Paper (11-12-2011) Bulk power transmission over long HVDC lines are preferred on account of Low cost of HVDC terminals Simple protection No harmonic problems Minimum line power losses Low cost of HVDC terminals Simple protection No harmonic problems Minimum line power losses ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) If the dielectric strength of the medium between the contacts builds up more rapidly than the restriking voltage the arc will Extinguish Increase in size Restrike Decrease in size Extinguish Increase in size Restrike Decrease in size ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The main advantage of using fractional pitch winding is to refuce Size of the machine Amount of copper in the winding Harmonics in the generated emf Cost of the machine Size of the machine Amount of copper in the winding Harmonics in the generated emf Cost of the machine ANSWER EXPLANATION DOWNLOAD EXAMIANS APP due to fractional pitch EMF can be approximately made into sine wavelosses due to harmonics reducedsaving in conductor materialmechanical strength of coil is increased.
DGVCL Exam Paper (11-12-2011) The circuit breaker generally used in railway traction is Vacuum CB Bulk Oil CB Air break CB Minimum Oil CB Vacuum CB Bulk Oil CB Air break CB Minimum Oil CB ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Lagging power factor 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 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) Different computers are connected to a LAN by a cable and a Modem Telephone line Interface card Special wires Modem Telephone line Interface card Special wires ANSWER DOWNLOAD EXAMIANS APP
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