DGVCL Exam Paper (11-12-2011) The circuit breaker generally used in railway traction is Minimum Oil CB Air break CB Vacuum CB Bulk Oil CB Minimum Oil CB Air break CB Vacuum CB Bulk Oil CB ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Due to skin effect Portion of the conductor near the surface carries more current and the core of the conductor carries less current Current flows through the half cross section of the conductor Portion of the conductor near the surface carries less current and the core of the conductor carries more current Uniform current flows through the conductor Portion of the conductor near the surface carries more current and the core of the conductor carries less current Current flows through the half cross section of the conductor Portion of the conductor near the surface carries less current and the core of the conductor carries more current Uniform current flows through the conductor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Skin Effect:tendency of the current to crowd near the conductor surface.Skin effect is proportional to frequency, conductor diameter and permiability. Skin effect increases effective resistance of conductor.In DC, no skin effect.
DGVCL Exam Paper (11-12-2011) The purpose of providing a choke in a tube light is To improve the power factor To limit the current to an appropriate value To avoid radio interference To eliminate corona effect To improve the power factor To limit the current to an appropriate value To avoid radio interference To eliminate corona effect ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The corona effect can be minimized by increasing Diameter of the conductor Spacing between the conductors Both spacing between the conductors and diameter of the conductor The length of the conductor Diameter of the conductor Spacing between the conductors Both spacing between the conductors and diameter of the conductor The length of the conductor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Corona can be reduced by using large size of conductor, bundle conductor and hollow conductor.
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 unity Current is minimum and power factor is unity Current is maximum and power factor is 0.5 Current is minimum and power factor is 0.5 Current is maximum and power factor is unity Current is minimum and power factor is unity Current is maximum and power factor is 0.5 ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Bulk power transmission over long HVDC lines are preferred on account of Minimum line power losses Low cost of HVDC terminals No harmonic problems Simple protection Minimum line power losses Low cost of HVDC terminals No harmonic problems Simple protection ANSWER DOWNLOAD EXAMIANS APP
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