DGVCL Exam Paper (11-12-2011) The positive and negative sequence impedance of a transmission line are Different Infinite Zero Equal Different Infinite Zero Equal ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The transient stability of a power system can be improved by Phase shifting transformer Increasing the turbine valve opening Excitation control Single pole switching of circuit breakers Phase shifting transformer Increasing the turbine valve opening Excitation control Single pole switching of circuit breakers ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Hysteresis in an instrument means The inaccuracy due to change in temperature The reliability of the instrument The change in the same reading when the input is first increased and then decreased The repeatability of the instrument The inaccuracy due to change in temperature The reliability of the instrument The change in the same reading when the input is first increased and then decreased The repeatability of the instrument ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The efficiency of a transformer at full load, 0.8 p.f. lag is 90%. Its efficiency at full load, 0.8 p.f. lead will be 80 % More than 90% 90 % Less than 90% 80 % More than 90% 90 % Less than 90% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Efficiency= output power/input powerefficiency = (v*i*cosφ)/((v*i*cosφ)+(x² Pc)+(Pi)) x=fractional part of full load
DGVCL Exam Paper (11-12-2011) Due to skin effect 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 Current flows through the half cross section of 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) A fuse wire should have Low specific resistance and high melting point Low specific resistance and low melting point High specific resistance and high melting point High specific resistance and low melting point Low specific resistance and high melting point Low specific resistance and low melting point High specific resistance and high melting point High specific resistance and low melting point ANSWER DOWNLOAD EXAMIANS APP
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