DGVCL Exam Paper (11-12-2011) Hysteresis in an instrument means The reliability of the instrument The change in the same reading when the input is first increased and then decreased The repeatability of the instrument The inaccuracy due to change in temperature The reliability of the instrument The change in the same reading when the input is first increased and then decreased The repeatability of the instrument The inaccuracy due to change in temperature 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 80 % More than 90% Less than 90% 90 % 80 % More than 90% 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) The purpose of interpoles in DC machines is to nullify The cross-magnetizing effect of armature mmf The reactance voltage The demagnetizing effect of armature mmf Both the cross-magnetizing mmf and the reactance voltage The cross-magnetizing effect of armature mmf The reactance voltage The demagnetizing effect of armature mmf Both the cross-magnetizing mmf and the reactance voltage 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 the dielectric strength of the medium between the contacts builds up more rapidly than the restriking voltage the arc will Restrike Extinguish Increase in size Decrease in size Restrike Extinguish Increase in size Decrease in size ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An AC series circuit has R = 6 Ω, XL = 20 Ω and Xc = 12 Ω. The ciruit power factor will be 0.5 leading 0.8 lagging 0.6 lagging 0.6 leading 0.5 leading 0.8 lagging 0.6 lagging 0.6 leading 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 Negative cycle of sine wave AC DC Positive cycle of sine wave Negative cycle of sine wave AC DC ANSWER DOWNLOAD EXAMIANS APP
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