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.

100 m
400 m
300 m
200 m

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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)
A three-phase 400 V, 6-pole, 50 Hz squirrel-cage induction motor is running at a slip of 5%. The speed of rotor with respect to stator magnetic field and speed of the stator magnetic field with respect to rotor magnetic field are

-50 rpm, 1000 rpm
950 rpm, zero
950 rpm, 1000 rpm
-50 rpm, zero

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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.

1.32 Hz
1.52 Hz
1.62 Hz
1.42 Hz

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