DGVCL Exam Paper (11-12-2011) If the voltage at the two ends of a line are 132 kV, and its reactance is 40 Ω, the stability limit of the line is 500 MW 435.6 MW 217.8 MW 251.5 MW 500 MW 435.6 MW 217.8 MW 251.5 MW ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which of the following correctly represents the sequence of operations of isolator, circiut breaker and earthing switch while opening a circuit? Close circuit breaker-close isolator - open earthing switch Open circuit breaker-open isolator-close earthing switch Close earthing switch - open ciruit- breaker-open islotor Open isolator close circuit breaker-open earthing switch Close circuit breaker-close isolator - open earthing switch Open circuit breaker-open isolator-close earthing switch Close earthing switch - open ciruit- breaker-open islotor Open isolator close circuit breaker-open earthing switch 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 4 % 0.4 % 6 % 5 % 4 % 0.4 % 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) An over excited synchronous motor draws current at Lagging power factor Depends on nature of load Unity power factor Leading power factor Lagging power factor Depends on nature of load Unity power factor 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) If the percentage reactance of the system upto the point of fault is 20% and the base kVA is 10,000 the short ciruit kVA is 60 MVA 20 MVA 10 MVA 50 MVA 60 MVA 20 MVA 10 MVA 50 MVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA = Base kVA/%X
DGVCL Exam Paper (11-12-2011) If the fault current is 2000 A, the relay plug setting is 50% and the CT ratio is 400/5, the plug setting multiple will be 25 50 15 10 25 50 15 10 ANSWER DOWNLOAD EXAMIANS APP
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