DGVCL Exam Paper (11-12-2011) Bulk power transmission over long HVDC lines are preferred on account of No harmonic problems Minimum line power losses Low cost of HVDC terminals Simple protection No harmonic problems Minimum line power losses Low cost of HVDC terminals Simple protection ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The transient stability of a power system can be improved by Increasing the turbine valve opening Excitation control Phase shifting transformer Single pole switching of circuit breakers Increasing the turbine valve opening Excitation control Phase shifting transformer Single pole switching of circuit breakers ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Fot fast load flow calculations, the best method is Newton-Raphson Approximate method Gauss-Siedal De-coupled method Newton-Raphson Approximate method Gauss-Siedal De-coupled method ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The bus bar zone faults are generally Single line to ground faults Phase to phase faults Three phase short ciruits Double line to ground faults Single line to ground faults Phase to phase faults Three phase short ciruits Double line to ground faults ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Ybus used in power flow studies and Zbus used in short circuit studies Have no inter relation Are transpose of each other Are the same Are inverse of each other Have no inter relation Are transpose of each other Are the same Are inverse 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 6 % 0.4 % 4 % 5 % 6 % 0.4 % 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%
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