DGVCL Exam Paper (11-12-2011) Reactance relay is used to protect against Earth faults only Both phase and earth faults Over voltage faults Phase faults only Earth faults only Both phase and earth faults Over voltage faults Phase faults only ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Bulk power transmission over long HVDC lines are preferred on account of Low cost of HVDC terminals No harmonic problems Minimum line power losses Simple protection Low cost of HVDC terminals No harmonic problems Minimum line power losses Simple protection ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Two parallel conductors are carrying the current in the same direction. Which of the following statements is correct? There is an attracting force between the conductors The force increases when the distance between the conductors is increased There is a repelling force between the conductors The force increases when the distance between the conductors is decreased There is an attracting force between the conductors The force increases when the distance between the conductors is increased There is a repelling force between the conductors The force increases when the distance between the conductors is decreased 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 6 % 4 % 5 % 0.4 % 6 % 4 % 5 % 0.4 % 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 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) If a relay fails to operate inspite of a fault in its own zone of protection, it is said to Under reach Pick up Reach Over reach Under reach Pick up Reach Over reach ANSWER DOWNLOAD EXAMIANS APP
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