DGVCL Exam Paper (11-12-2011) The circuit breaker generally used in railway traction is Minimum Oil CB Vacuum CB Air break CB Bulk Oil CB Minimum Oil CB Vacuum CB Air break CB Bulk Oil CB ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The efficiency of a transformer at full load, 0.8 p.f. lag is 90%. Its efficiency at full load, 0.8 p.f. lead will be More than 90% 80 % Less than 90% 90 % More than 90% 80 % Less than 90% 90 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Efficiency= output power/input powerefficiency = (v*i*cosφ)/((v*i*cosφ)+(x² Pc)+(Pi)) x=fractional part of full load
DGVCL Exam Paper (11-12-2011) Transposition of transmission line is done to Reduce skin effect Balance line voltage drop Reduce corona Reduce line loss Reduce skin effect Balance line voltage drop Reduce corona Reduce line loss 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? Open circuit breaker-open isolator-close earthing switch Close earthing switch - open ciruit- breaker-open islotor Close circuit breaker-close isolator - open earthing switch Open isolator close circuit breaker-open earthing switch Open circuit breaker-open isolator-close earthing switch Close earthing switch - open ciruit- breaker-open islotor Close circuit breaker-close isolator - open earthing switch Open isolator close circuit breaker-open earthing switch ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) It is difficult interrupt a capacitive current because Stored energy in the capacitor is very high Current magnitude is very small It has a leading power factor The restriking voltage can be high Stored energy in the capacitor is very high Current magnitude is very small It has a leading power factor The restriking voltage can be high 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
EXAMIANS