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 leading 0.6 lagging 0.5 leading 0.8 lagging 0.6 leading 0.6 lagging ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The main criterion for the design of a distributor is Corona loss Voltage drop Temperature rise Radio interference Corona loss Voltage drop Temperature rise Radio interference ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The insulation coordination for UHV lines (above 500 kV) is done based on Lightning and switching surges Lightning surges Switching surges Voltage level of the line Lightning and switching surges Lightning surges Switching surges Voltage level of the line ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) An IDMT relay provides A definite time characteristic for low values of the failt current and an inverse characteristic for high values of the fault current A definite time cuttent characteristic An inverse time current characteristic An inverse characteristic for low values of the fault current and a definite time characteristic for high values of the fault current A definite time characteristic for low values of the failt current and an inverse characteristic for high values of the fault current A definite time cuttent characteristic An inverse time current characteristic An inverse characteristic for low values of the fault current and a definite time characteristic for high values of the fault current ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Due to skin effect Portion of the conductor near the surface carries more current and the core of the conductor carries less current Portion of the conductor near the surface carries less current and the core of the conductor carries more current Uniform current flows through the conductor Current flows through the half cross section of the conductor Portion of the conductor near the surface carries more current and the core of the conductor carries less current Portion of the conductor near the surface carries less current and the core of the conductor carries more current Uniform current flows through the conductor Current flows through the half cross section of the conductor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Skin Effect:tendency of the current to crowd near the conductor surface.Skin effect is proportional to frequency, conductor diameter and permiability. Skin effect increases effective resistance of conductor.In DC, no skin effect.
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 % 4 % 0.4 % 6 % 5 % 4 % 0.4 % 6 % 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%
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