DGVCL Exam Paper (11-12-2011) Which type of back up protection is widely used for the protection of transmission lines? Breaker backup Control backup Relay backup Remote backup Breaker backup Control backup Relay backup Remote backup 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 % 0.4 % 4 % 5 % 6 % 0.4 % 4 % 5 % 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 advantage of slipring induction motor over the squirrel cage induction motor is 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 It's power factor is higher It can be started with the help of rotor resistances 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) In carrier current protection, the purpose of the wave trap is for Trapping power frequency waves All of these Tripping fault current Trapping high frequency waves entering into generator/transformer unit. Trapping power frequency waves All of these Tripping fault current Trapping high frequency waves entering into generator/transformer unit. ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) If the dielectric strength of the medium between the contacts builds up more rapidly than the restriking voltage the arc will Decrease in size Restrike Increase in size Extinguish Decrease in size Restrike Increase in size Extinguish ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) It is difficult interrupt a capacitive current because The restriking voltage can be high It has a leading power factor Stored energy in the capacitor is very high Current magnitude is very small The restriking voltage can be high It has a leading power factor Stored energy in the capacitor is very high Current magnitude is very small ANSWER DOWNLOAD EXAMIANS APP
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