DGVCL Exam Paper (11-12-2011) The circuit breaker generally used in railway traction is Air break CB Bulk Oil CB Minimum Oil CB Vacuum CB Air break CB Bulk Oil CB Minimum Oil CB Vacuum 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 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 It's power factor is higher It can be started with the help of rotor resistances It is suitable for higher speeds 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) If a relay fails to operate inspite of a fault in its own zone of protection, it is said to Pick up Over reach Under reach Reach Pick up Over reach Under reach Reach 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 6 % 4 % 5 % 0.4 % 6 % 4 % 5 % 0.4 % 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) If the excitation of a synchronous generator fails, it acts as a Synchronous generator Synchronous motor Induction generator Induction motor Synchronous generator Synchronous motor Induction generator Induction motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP if excitation of synchronous generator fails, operate as induction motor
DGVCL Exam Paper (11-12-2011) The corona effect can be minimized by increasing Spacing between the conductors Diameter of the conductor The length of the conductor Both spacing between the conductors and diameter of the conductor Spacing between the conductors Diameter of the conductor The length of the conductor Both spacing between the conductors and diameter of the conductor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Corona can be reduced by using large size of conductor, bundle conductor and hollow conductor.
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