DGVCL Exam Paper (11-12-2011) The corona effect can be minimized by increasing The length of the conductor Both spacing between the conductors and diameter of the conductor Spacing between the conductors Diameter of the conductor The length of the conductor Both spacing between the conductors and diameter of the conductor Spacing between the conductors Diameter 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) 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 % More than 90% Less than 90% 90 % 80 % More than 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) The main criterion for the design of a distributor is Voltage drop Corona loss Radio interference Temperature rise Voltage drop Corona loss Radio interference Temperature rise ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which motor is used to start heavy loads? Series motor Cumulatively compounded motor Shunt motor Differentially compounded motor Series motor Cumulatively compounded motor Shunt motor Differentially compounded motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Torque in d.c motor = k* φ * IaIn series motor φ α IaTα I²starting torque of dc series motor is high
DGVCL Exam Paper (11-12-2011) The bus bar zone faults are generally Phase to phase faults Three phase short ciruits Double line to ground faults Single line to ground faults Phase to phase faults Three phase short ciruits Double line to ground faults Single line to ground faults ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) What type of insulator is used if the direction of the transmission line is to be changed? Suspebsion type Pin type Strain type Shakle type Suspebsion type Pin type Strain type Shakle type ANSWER DOWNLOAD EXAMIANS APP
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