DGVCL Exam Paper (11-12-2011) A fuse is inserted in Earth continuity conductor Neutral wire Both phased and neutral wire Phase wire Earth continuity conductor Neutral wire Both phased and neutral wire Phase wire ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A 3 phase, 6 pole induction motor operates on 440 V, 50 Hz, supply. If the actual speed of the motor is 960 rpm the slip will be 5 % 6 % 0.4 % 4 % 5 % 6 % 0.4 % 4 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ns = 120f/PSlip=(Ns-Nr)/NsNs = 1000 and Nr = 960 from equation of slip, S = (1000-960)/1000S = 0.04 or 4%
DGVCL Exam Paper (11-12-2011) The main advantage of using fractional pitch winding is to refuce Harmonics in the generated emf Size of the machine Cost of the machine Amount of copper in the winding Harmonics in the generated emf Size of the machine Cost of the machine Amount of copper in the winding 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) An over excited synchronous motor draws current at Unity power factor Depends on nature of load Leading power factor Lagging power factor Unity power factor Depends on nature of load Leading power factor Lagging power factor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Over excitation : leading currentUnder excitation : lagging currentNormal excitation : current with unity PF (in phase current)
DGVCL Exam Paper (11-12-2011) In carrier current protection, the purpose of the wave trap is for Trapping high frequency waves entering into generator/transformer unit. Tripping fault current All of these Trapping power frequency waves Trapping high frequency waves entering into generator/transformer unit. Tripping fault current All of these Trapping power frequency waves 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 Cold reserve Firm power Hot reserve Spinning reserve Cold reserve Firm power Hot reserve Spinning reserve ANSWER DOWNLOAD EXAMIANS APP
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