DGVCL Exam Paper (11-12-2011) An IDMT relay provides A definite time cuttent characteristic A definite time characteristic for low values of the failt current and an inverse characteristic for high values of the fault current An inverse characteristic for low values of the fault current and a definite time characteristic for high values of the fault current An inverse time current characteristic A definite time cuttent characteristic A definite time characteristic for low values of the failt current and an inverse characteristic for high values of the fault current An inverse characteristic for low values of the fault current and a definite time characteristic for high values of the fault current An inverse time current characteristic ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In a power plant, a reserve generating capacity which is not in service but is in operation is known as Hot reserve Cold reserve Firm power Spinning reserve Hot reserve Cold reserve Firm power Spinning reserve 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 90 % 80 % More than 90% Less than 90% 90 % 80 % More than 90% Less 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) The corona effect can be minimized by increasing Diameter of the conductor Both spacing between the conductors and diameter of the conductor Spacing between the conductors The length of the conductor Diameter of the conductor Both spacing between the conductors and diameter of the conductor Spacing between the conductors The length of the conductor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Corona can be reduced by using large size of conductor, bundle conductor and hollow conductor.
DGVCL Exam Paper (11-12-2011) It is difficult interrupt a capacitive current because Stored energy in the capacitor is very high It has a leading power factor The restriking voltage can be high Current magnitude is very small Stored energy in the capacitor is very high It has a leading power factor The restriking voltage can be high Current magnitude is very small ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In which of the following motors, the stator and rotor magnetic fields rotate at the same speed? Universal motor Reluctance motor Synchronous motor Induction motor Universal motor Reluctance motor Synchronous motor Induction motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In all machine stator and rotor magnetic field rotates (stationary with respect to each other) at synchronous speed with respect to stationary observer.