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 0.4 % 5 % 6 % 4 % 0.4 % 5 % 6 % 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) A fuse wire should have Low specific resistance and low melting point High specific resistance and low melting point High specific resistance and high melting point Low specific resistance and high melting point Low specific resistance and low melting point High specific resistance and low melting point High specific resistance and high melting point Low specific resistance and high melting point ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) It is difficult interrupt a capacitive current because Stored energy in the capacitor is very high The restriking voltage can be high It has a leading power factor Current magnitude is very small Stored energy in the capacitor is very high The restriking voltage can be high It has a leading power factor Current magnitude is very small ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Ybus used in power flow studies and Zbus used in short circuit studies Are the same Are transpose of each other Have no inter relation Are inverse of each other Are the same Are transpose of each other Have no inter relation Are inverse of each other ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In carrier current protection, the purpose of the wave trap is for All of these Trapping high frequency waves entering into generator/transformer unit. Tripping fault current Trapping power frequency waves All of these Trapping high frequency waves entering into generator/transformer unit. Tripping fault current Trapping power frequency waves ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which motor is used to start heavy loads? Series motor Differentially compounded motor Cumulatively compounded motor Shunt motor Series motor Differentially compounded 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
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