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 0.6 lagging 0.6 leading 0.5 leading 0.8 lagging 0.6 lagging 0.6 leading 0.5 leading 0.8 lagging ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The circuit breaker generally used in railway traction is Bulk Oil CB Vacuum CB Air break CB Minimum Oil CB Bulk Oil CB Vacuum CB Air break CB Minimum Oil CB ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Fot fast load flow calculations, the best method is De-coupled method Gauss-Siedal Newton-Raphson Approximate method De-coupled method Gauss-Siedal Newton-Raphson Approximate method ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Due to skin effect Current flows through the half cross section of the conductor 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 Portion of the conductor near the surface carries less current and the core of the conductor carries more current Current flows through the half cross section of the conductor 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 Portion of the conductor near the surface carries less current and the core of the conductor carries more current 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) Bulk power transmission over long HVDC lines are preferred on account of No harmonic problems Minimum line power losses Simple protection Low cost of HVDC terminals No harmonic problems Minimum line power losses Simple protection Low cost of HVDC terminals ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Buchholz relay causes Tripping for both major and minor faults Tripping for minor faults and alarm for major faults Alarm for both major and minor faults Tripping for major faults and alarm for minor faults Tripping for both major and minor faults Tripping for minor faults and alarm for major faults Alarm for both major and minor faults Tripping for major faults and alarm for minor faults ANSWER DOWNLOAD EXAMIANS APP