DGVCL Exam Paper (11-12-2011) Under operating conditions, the secondary of a current transformer is always short ciruited because It is safe to human beings It protects the primary ciruits It avoids core saturation and high voltage induction It protects the secondary ciruits It is safe to human beings It protects the primary ciruits It avoids core saturation and high voltage induction It protects the secondary ciruits ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) First zone distance relay protects the transmission line section upto 25 % of its full length Its full length 80 % of its full length 50 % of its full length 25 % of its full length Its full length 80 % of its full length 50 % of its full length ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The advantage of slipring induction motor over the squirrel cage induction motor is It is suitable for higher speeds It can be started with the help of rotor resistances It has a higher efficiency It's power factor is higher It is suitable for higher speeds It can be started with the help of rotor resistances It has a higher efficiency It's power factor is higher ANSWER EXPLANATION DOWNLOAD EXAMIANS APP slip ring motor have high starting torque compare to squirrel cage motor and have good speed controlalso have high over loading capacity, smooth acceleration under heavy loads.
DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Unity power factor Lagging power factor Leading power factor Depends on nature of load Unity power factor Lagging power factor Leading power factor Depends on nature of load ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Over excitation : leading currentUnder excitation : lagging currentNormal excitation : current with unity PF (in phase current)
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 % Less than 90% More than 90% 80 % 90 % Less than 90% More than 90% 80 % 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) A fuse is inserted in Neutral wire Both phased and neutral wire Phase wire Earth continuity conductor Neutral wire Both phased and neutral wire Phase wire Earth continuity conductor ANSWER DOWNLOAD EXAMIANS APP
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