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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MGVCL Exam Paper (30-07-2021 Shift 3)
In a 3-phase, 4-wire, 400/230 V system, a lamp (L₁) of 100 W is connected to one phase and neutral and a lamp (L₂) of 150 W is connected to the second pahse and neutral. If the neutral wire is disconnected accidently, what will be the voltage across a 150 W lamp (L₂)?

240 V
180 V
120 v
160 V

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MGVCL Exam Paper (30-07-2021 Shift 3)
A single phase motor connected to 400 V, 50 Hz supply takes 25 A at a power factor of 0.75 lagging. Calculate the capacitance required in parallel with the motor to raise the power factor to 0.95 lagging.

82.55 pF
62.55 pF
92.55 pF
72.55 pF

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MGVCL Exam Paper (30-07-2021 Shift 3)
The purpose of ____ is to check the ability of the circuit breaker to withstand the overvoltages at power frequency as well as undesired value of voltage during lightning and other discharge phenomenon.

dielectric test
synthetic test
short circuit test
routine test

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