DGVCL Exam Paper (11-12-2011) A device connected to the computer which converts digital signals to analog and vice-versa is Keyboard Modem CPU UPS Keyboard Modem CPU UPS ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which motor is used to start heavy loads? Series motor Differentially compounded motor Cumulatively compounded motor Shunt motor Series motor Differentially compounded motor Cumulatively compounded motor Shunt motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Torque in d.c motor = k* φ * IaIn series motor φ α IaTα I²starting torque of dc series motor is high
DGVCL Exam Paper (11-12-2011) If the percentage reactance of the system upto the point of fault is 20% and the base kVA is 10,000 the short ciruit kVA is 60 MVA 10 MVA 50 MVA 20 MVA 60 MVA 10 MVA 50 MVA 20 MVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA = Base kVA/%X
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 90 % Less than 90% 80 % More than 90% 90 % Less than 90% 80 % 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) It is difficult interrupt a capacitive current because Stored energy in the capacitor is very high The restriking voltage can be high It has a leading power factor Current magnitude is very small Stored energy in the capacitor is very high The restriking voltage can be high It has a leading power factor Current magnitude is very small ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The mutual inductance between two unity coupled coils of 9 H and 4 H is 36 H 13 H 6 H 2.2 H 36 H 13 H 6 H 2.2 H ANSWER DOWNLOAD EXAMIANS APP
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