MGVCL Exam Paper (30-07-2021 Shift 3)
A 1000 kVA ONAN cooled transformer has a load of 500 kVA throughout the day except for a period of 2 hours. What is the permissible overload for a duration of two hours. Assume the permissible load kVA as a fraction of rated kVA is 1.43.

700 kVA
715 kVA
1430 kVA
1050 kVA

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MGVCL Exam Paper (30-07-2021 Shift 3)
A star connected synchronous generator rated at 500 MVA, 50 kV has a reactance of 0.5 pu. Find the ohmic value of the reactance.

0.1 Ω
0.25 Ω
1 Ω
2.5 Ω

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MGVCL Exam Paper (30-07-2021 Shift 3)
A 50 Hz synchronous generator is connected to an infinite bus through a line. The p.u. reactances of generator and the line are j0.4 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.

1.8 Hz
1.2 Hz
1.6 Hz
0.8 Hz

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