DGVCL Exam Paper (11-12-2011) Ybus used in power flow studies and Zbus used in short circuit studies Are inverse of each other Are the same Have no inter relation Are transpose of each other Are inverse of each other Are the same Have no inter relation Are transpose of each other 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 % 5 % 6 % 0.4 % 4 % 5 % 6 % 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) The purpose of interpoles in DC machines is to nullify Both the cross-magnetizing mmf and the reactance voltage The demagnetizing effect of armature mmf The reactance voltage The cross-magnetizing effect of armature mmf Both the cross-magnetizing mmf and the reactance voltage The demagnetizing effect of armature mmf The reactance voltage 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) If a relay fails to operate inspite of a fault in its own zone of protection, it is said to Over reach Under reach Pick up Reach Over reach Under reach Pick up Reach ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The insulation coordination for UHV lines (above 500 kV) is done based on Lightning surges Voltage level of the line Switching surges Lightning and switching surges Lightning surges Voltage level of the line Switching surges Lightning and switching surges ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Rated making capacity of a ciruit breaker is equal to 2.55 X rated symmetrical breaking capacity √2 X rated symmetrical breaking capacity Rated symmetrical breaking capacity 1.11 X rated symmetrical breaking capacity 2.55 X rated symmetrical breaking capacity √2 X rated symmetrical breaking capacity Rated symmetrical breaking capacity 1.11 X rated symmetrical breaking capacity ANSWER DOWNLOAD EXAMIANS APP
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