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 4 % 5 % 0.4 % 6 % 4 % 5 % 0.4 % 6 % 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) An AC series circuit has R = 6 Ω, XL = 20 Ω and Xc = 12 Ω. The ciruit power factor will be 0.8 lagging 0.6 lagging 0.5 leading 0.6 leading 0.8 lagging 0.6 lagging 0.5 leading 0.6 leading ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A fuse wire should have High specific resistance and high melting point Low specific resistance and high melting point High specific resistance and low melting point Low specific resistance and low melting point High specific resistance and high melting point Low specific resistance and high melting point High specific resistance and low melting point Low specific resistance and low melting point ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In a series RLC circuit at resonance Current is maximum and power factor is unity Current is minimum and power factor is 0.5 Current is minimum and power factor is unity Current is maximum and power factor is 0.5 Current is maximum and power factor is unity Current is minimum and power factor is 0.5 Current is minimum and power factor is unity Current is maximum and power factor is 0.5 ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Hysteresis in an instrument means The reliability of the instrument The change in the same reading when the input is first increased and then decreased The repeatability of the instrument The inaccuracy due to change in temperature The reliability of the instrument The change in the same reading when the input is first increased and then decreased The repeatability of the instrument The inaccuracy due to change in temperature ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Lightning Magnetizing inrush current Unbalanced protection Switching over voltages Lightning Magnetizing inrush current Unbalanced protection Switching over voltages 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
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