MGVCL Exam Paper (30-07-2021 Shift 2)
A 50 Hz synchronous generator is connected to an infinite bus through a line. The p.u. reactances of generator and the line are j0.3 p.u. and j0.2 p.u. respectively. The generator no load voltage is 1.1 p.u. and that of infinite bus is 1.0 p.u. The inertia constant of the generator is 4 MW-sec/MVA. Determine the frequency of natural oscillations if the generator is loaded to 60% of its maximum power transfer capacity and small perturbation in power is given.

1.42 Hz
1.32 Hz
1.52 Hz
1.62 Hz

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MGVCL Exam Paper (30-07-2021 Shift 2)
Which one of these is not a monitoring and diagnostic test for transformer oil?

Furanic Compound Analysis
Dissolved Gas Analysis
Volatility Level Analysis
Dissolved Metals Analysis

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MGVCL Exam Paper (30-07-2021 Shift 2)
In a short circuit test on circuit breaker, time to reach the peak re-striking voltage is 50 µs with the peak restriking voltage of 100 kV. Determine average RRRV (Rate of rise re-striking voltage)?

4 x 10⁶ kV/sec
1 x 10⁶ kV/sec
3 x 10⁶ kV/sec
2 x 10⁶ kV/sec

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MGVCL Exam Paper (30-07-2021 Shift 2)
In a test by Murray loop for ground fault on 600 m of cable having a resistance of 1.5 Ω/km, the faulty cable is looped with a sound cable of the same length and area of cross section. If the ratio of the other two arms of the testing network at balance is 3 : 1, find the distance of the fault from the testing end of cables.

200 m
100 m
300 m
400 m

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