DGVCL Exam Paper (11-12-2011) The mutual inductance between two unity coupled coils of 9 H and 4 H is 13 H 36 H 6 H 2.2 H 13 H 36 H 6 H 2.2 H ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Magnetizing inrush current Switching over voltages Lightning Unbalanced protection Magnetizing inrush current Switching over voltages Lightning Unbalanced protection 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
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 % 0.4 % 6 % 5 % 4 % 0.4 % 6 % 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) Bulk power transmission over long HVDC lines are preferred on account of Simple protection Minimum line power losses No harmonic problems Low cost of HVDC terminals Simple protection Minimum line power losses No harmonic problems Low cost of HVDC terminals ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The main criterion for the design of a distributor is Radio interference Temperature rise Voltage drop Corona loss Radio interference Temperature rise Voltage drop Corona loss ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) First zone distance relay protects the transmission line section upto Its full length 25 % of its full length 50 % of its full length 80 % of its full length Its full length 25 % of its full length 50 % of its full length 80 % of its full length ANSWER DOWNLOAD EXAMIANS APP
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