DGVCL Exam Paper (11-12-2011) A device connected to the computer which converts digital signals to analog and vice-versa is CPU Keyboard UPS Modem CPU Keyboard UPS Modem 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 Less than 90% More than 90% 90 % 80 % Less than 90% More than 90% 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) Fot fast load flow calculations, the best method is Newton-Raphson Approximate method De-coupled method Gauss-Siedal Newton-Raphson Approximate method De-coupled method Gauss-Siedal ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) DC series motors are best suited for traction work because Torque and speed are inversely proportional to the square of the armature current Its torque is proportional to the square of the armature current and speed is inversely proportional to torque Torque and speed are proportional to the square of the armature current Its torque is proportional to the square of the armature current and speed is directional proporational to torque Torque and speed are inversely proportional to the square of the armature current Its torque is proportional to the square of the armature current and speed is inversely proportional to torque Torque and speed are proportional to the square of the armature current Its torque is proportional to the square of the armature current and speed is directional proporational to torque ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Torque in d.c motor = k* φ * IaIn series motor φ α IaTα I²N α 1/φN α 1/T
DGVCL Exam Paper (11-12-2011) If a 5 A fuse is blown frequently in a house lighting circuit, it is required to Reduce the load Insert a fuse of higher voltage rating Check the load Insert a fuse of higher current rating Reduce the load Insert a fuse of higher voltage rating Check the load Insert a fuse of higher current rating ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Leading power factor Unity power factor Lagging power factor Depends on nature of load Leading power factor Unity power factor Lagging 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)
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