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.
In the cables, the location of fault is usually found out by comparing the capacitances of insulated conductors.
The current carrying capacity of cables in DC is less than that in AC.
In the cables, sheaths are used to provide enough strength.

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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

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

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

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MGVCL Exam Paper (30-07-2021 Shift 2)
In the circuit of figure, the switch is closed to position-1 for a long time. At t = 0 the switch position is changed from postion-1 to postion-2. Find an expression for the current i(t).

i(t) = (E/R) cos[1/√(LC)]t A
i(t) = (E/R) cos√(LC) t A
i(t) = (E/R) sin√(LC) t A
i(t) = (E/R) sin[1/√(LC)]t A

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