DGVCL Exam Paper (11-12-2011) The purpose of providing a choke in a tube light is To limit the current to an appropriate value To eliminate corona effect To avoid radio interference To improve the power factor To limit the current to an appropriate value To eliminate corona effect To avoid radio interference To improve the power factor ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which of the following power distribution system gives better reliabity ? Ring main system Radial system DC 3 wire system None of these Ring main system Radial system DC 3 wire system None of these ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The main advantage of using fractional pitch winding is to refuce 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 Harmonics in the generated emf 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) Which motor is used to start heavy loads? Cumulatively compounded motor Series motor Differentially compounded motor Shunt motor Cumulatively compounded motor Series motor Differentially 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) In the protection of transformers, harmonic restraint is used to guard against Unbalanced protection Magnetizing inrush current Lightning Switching over voltages Unbalanced protection Magnetizing inrush current Lightning Switching over voltages ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Initial inrush of magnetizing currents have high component of even and odd harmonics.2nd - 63%3rd -26.8%4th- 5.1%5th- 4.1%6th- 3.77th-2.4
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 Hot reserve Firm power Spinning reserve Cold reserve Hot reserve Firm power Spinning reserve ANSWER DOWNLOAD EXAMIANS APP
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