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 80 % Less than 90% 90 % More than 90% 80 % Less than 90% 90 % More than 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 Balance line voltage drop Reduce line loss Reduce skin effect Reduce corona Balance line voltage drop Reduce line loss Reduce skin effect Reduce corona ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) It is difficult interrupt a capacitive current because The restriking voltage can be high It has a leading power factor Stored energy in the capacitor is very high Current magnitude is very small The restriking voltage can be high It has a leading power factor Stored energy in the capacitor is very high Current magnitude is very small 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? The force increases when the distance between the conductors is decreased There is a repelling force between the conductors The force increases when the distance between the conductors is increased There is an attracting force between the conductors The force increases when the distance between the conductors is decreased There is a repelling force between the conductors The force increases when the distance between the conductors is increased There is an attracting force between the conductors ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Hysteresis in an instrument means The inaccuracy due to change in temperature The reliability of the instrument The repeatability of the instrument The change in the same reading when the input is first increased and then decreased The inaccuracy due to change in temperature The reliability of the instrument The repeatability of the instrument The change in the same reading when the input is first increased and then decreased ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) All the peripheral devices connected to a computer require power to work. Which of the following voltages is required for the motherboard to work? Positive cycle of sine wave DC AC Negative cycle of sine wave Positive cycle of sine wave DC AC Negative cycle of sine wave ANSWER DOWNLOAD EXAMIANS APP