DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Leading power factor Depends on nature of load Unity power factor Lagging power factor Leading power factor Depends on nature of load Unity power factor Lagging 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) Permittivity is expressed in terms of N/m Weber /m Farad/m farad/sq. m. N/m Weber /m Farad/m farad/sq. m. ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The purpose of providing a choke in a tube light is To limit the current to an appropriate value To avoid radio interference To improve the power factor To eliminate corona effect To limit the current to an appropriate value To avoid radio interference To improve the power factor To eliminate corona effect ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An AC series circuit has R = 6 Ω, XL = 20 Ω and Xc = 12 Ω. The ciruit power factor will be 0.6 leading 0.5 leading 0.6 lagging 0.8 lagging 0.6 leading 0.5 leading 0.6 lagging 0.8 lagging 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 0.4 % 4 % 6 % 5 % 0.4 % 4 % 6 % 5 % 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) At time t= 0+ , with zero initial condition, which of the following acts as a short circuit? Voltage source Conductor Resistor Capacitor Voltage source Conductor Resistor Capacitor ANSWER DOWNLOAD EXAMIANS APP
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