DGVCL Exam Paper (11-12-2011) In which of the following motors, the stator and rotor magnetic fields rotate at the same speed? Induction motor Reluctance motor Universal motor Synchronous motor Induction motor Reluctance motor Universal motor Synchronous motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In all machine stator and rotor magnetic field rotates (stationary with respect to each other) at synchronous speed with respect to stationary observer.
DGVCL Exam Paper (11-12-2011) Transposition of transmission line is done to Reduce skin effect Balance line voltage drop Reduce corona Reduce line loss Reduce skin effect Balance line voltage drop Reduce corona Reduce line loss 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 inverse of each other Have no inter relation Are transpose of each other Are the same Are inverse of each other Have no inter relation Are transpose of each other ANSWER DOWNLOAD EXAMIANS APP
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) 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) Which of the following power distribution system gives better reliabity ? DC 3 wire system Ring main system None of these Radial system DC 3 wire system Ring main system None of these Radial system ANSWER DOWNLOAD EXAMIANS APP
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