MGVCL Exam Paper (30-07-2021 Shift 2)
Which one of the following statement is TRUE?

Underground cables are laid at sufficient depth to avoid being unearthed easily due to removal of soil.
The current carrying capacity of cables in DC is less than that in AC.
In the cables, sheaths are used to provide enough strength.
In the cables, the location of fault is usually found out by comparing the capacitances of insulated conductors.

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MGVCL Exam Paper (30-07-2021 Shift 2)
Interposing current-transformer (CT) is used in differential protection of a transformer to

limit the main CT secondary current
increase the sensitivity of the relay
match the standard ratio of CTs used on both sides of the transformer winding
minimize the effect of saturation of the main CTs

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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
1.52 Hz
1.62 Hz
1.32 Hz

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