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 90 % 80 % Less than 90% More than 90% 90 % 80 % Less than 90% More 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) The effect of electric shock on the human body depends on Duration of contact All of these Current Voltage Duration of contact All of these Current Voltage ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Rated making capacity of a ciruit breaker is equal to 1.11 X rated symmetrical breaking capacity 2.55 X rated symmetrical breaking capacity √2 X rated symmetrical breaking capacity Rated symmetrical breaking capacity 1.11 X rated symmetrical breaking capacity 2.55 X rated symmetrical breaking capacity √2 X rated symmetrical breaking capacity Rated symmetrical breaking capacity ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A fuse wire should have 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 Low specific resistance and high melting point Low specific resistance and low melting point ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The corona effect can be minimized by increasing Both spacing between the conductors and diameter of the conductor Diameter of the conductor The length of the conductor Spacing between the conductors Both spacing between the conductors and diameter of the conductor Diameter of the conductor The length of the conductor Spacing between the conductors 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) The transient stability of a power system can be improved by Excitation control Single pole switching of circuit breakers Increasing the turbine valve opening Phase shifting transformer Excitation control Single pole switching of circuit breakers Increasing the turbine valve opening Phase shifting transformer ANSWER DOWNLOAD EXAMIANS APP
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