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 Less than 90% 90 % More than 90% 80 % Less than 90% 90 % More than 90% 80 % 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) A fuse is inserted in Earth continuity conductor Both phased and neutral wire Phase wire Neutral wire Earth continuity conductor Both phased and neutral wire Phase wire Neutral wire ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The main advantage of using fractional pitch winding is to refuce Harmonics in the generated emf Amount of copper in the winding Cost of the machine Size of the machine Harmonics in the generated emf Amount of copper in the winding Cost of the machine Size of the machine ANSWER EXPLANATION DOWNLOAD EXAMIANS APP due to fractional pitch EMF can be approximately made into sine wavelosses due to harmonics reducedsaving in conductor materialmechanical strength of coil is increased.
DGVCL Exam Paper (11-12-2011) Ybus used in power flow studies and Zbus used in short circuit studies Are the same Are inverse of each other Have no inter relation Are transpose of each other Are the same Are inverse of each other Have no inter relation Are transpose of each other ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The picture on the monitor of a computer is made up of tiny coloured dots called Pixels Icons Points Spots Pixels Icons Points Spots 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 Spinning reserve Firm power Cold reserve Hot reserve Spinning reserve Firm power Cold reserve Hot reserve ANSWER DOWNLOAD EXAMIANS APP
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