DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at 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 Leading power factor 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 purpose of providing a choke in a tube light is To improve the power factor To eliminate corona effect To avoid radio interference To limit the current to an appropriate value To improve the power factor To eliminate corona effect To avoid radio interference To limit the current to an appropriate value ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A 3 phase, 6 pole induction motor operates on 440 V, 50 Hz, supply. If the actual speed of the motor is 960 rpm the slip will be 5 % 4 % 0.4 % 6 % 5 % 4 % 0.4 % 6 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ns = 120f/PSlip=(Ns-Nr)/NsNs = 1000 and Nr = 960 from equation of slip, S = (1000-960)/1000S = 0.04 or 4%
DGVCL Exam Paper (11-12-2011) Fot fast load flow calculations, the best method is Gauss-Siedal Newton-Raphson Approximate method De-coupled method Gauss-Siedal Newton-Raphson Approximate method De-coupled method ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A Mho relay is a Directional restrained over current relay Directional restrained over voltage relay Voltage controlled over current relay Voltage restrained directional relay Directional restrained over current relay Directional restrained over voltage relay Voltage controlled over current relay Voltage restrained directional relay ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The main criterion for the design of a distributor is Temperature rise Corona loss Voltage drop Radio interference Temperature rise Corona loss Voltage drop Radio interference ANSWER DOWNLOAD EXAMIANS APP