DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Magnetizing inrush current Lightning Switching over voltages Unbalanced protection Magnetizing inrush current Lightning Switching over voltages Unbalanced protection 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) At time t= 0+ , with zero initial condition, which of the following acts as a short circuit? Voltage source Capacitor Conductor Resistor Voltage source Capacitor Conductor Resistor ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The circuit breaker generally used in railway traction is Air break CB Bulk Oil CB Vacuum CB Minimum Oil CB Air break CB Bulk Oil CB Vacuum CB Minimum Oil CB ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The advantage of slipring induction motor over the squirrel cage induction motor is It's power factor is higher It can be started with the help of rotor resistances It is suitable for higher speeds It has a higher efficiency It's power factor is higher It can be started with the help of rotor resistances It is suitable for higher speeds It has a higher efficiency ANSWER EXPLANATION DOWNLOAD EXAMIANS APP slip ring motor have high starting torque compare to squirrel cage motor and have good speed controlalso have high over loading capacity, smooth acceleration under heavy loads.
DGVCL Exam Paper (11-12-2011) Which of the following power distribution system gives better reliabity ? Radial system DC 3 wire system None of these Ring main system Radial system DC 3 wire system None of these Ring main system ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which motor is used to start heavy loads? Differentially compounded motor Series motor Cumulatively compounded motor Shunt motor Differentially compounded motor Series motor Cumulatively 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
EXAMIANS