DGVCL Exam Paper (11-12-2011) At time t= 0+ , with zero initial condition, which of the following acts as a short circuit? Conductor Resistor Voltage source Capacitor Conductor Resistor Voltage source Capacitor ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The purpose of interpoles in DC machines is to nullify Both the cross-magnetizing mmf and the reactance voltage The reactance voltage The demagnetizing effect of armature mmf The cross-magnetizing effect of armature mmf Both the cross-magnetizing mmf and the reactance voltage The reactance voltage The demagnetizing effect of armature mmf The cross-magnetizing effect of armature mmf ANSWER EXPLANATION DOWNLOAD EXAMIANS APP interpoles is widely use to improve commutationplace between main poles fitted to yokefunctions:to neutralize armature mmf in commutating zoneto produce some flux in commutating zone
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 6 % 4 % 0.4 % 5 % 6 % 4 % 0.4 % 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) Which of the following power distribution system gives better reliabity ? Ring main system Radial system DC 3 wire system None of these Ring main system Radial system DC 3 wire system None of these ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Depends on nature of load Lagging power factor Leading power factor Unity power factor Depends on nature of load Lagging power factor Leading power factor Unity 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 positive and negative sequence impedance of a transmission line are Different Zero Infinite Equal Different Zero Infinite Equal ANSWER DOWNLOAD EXAMIANS APP
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