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03000EE301092002

PART D
Answer any two full questions, each carries 10 marks.
With neat figure explain the following:
(a) Arc Voltage (b) Restriking Voltage (c) Recovery Voltage
Explain the working principle of electromagnetic induction type relays.
Explain the basic protection scheme employed using microprocessor.
With neat figure explain principle of operation of thermal relays.
An electric train runs between two sub-stations 6km apart maintained at
voltages 600V and 59017 respectively and draws a constant current of 300A
while in motion. The track resistance of go and return path is 0.04Q/km.
Calculate:
(i) The point along the track where minimum potential occurs
(ii) | The current supplied by the two sub-stations when the train is at the
point of minimum potential.

Write short notes on insulation coordination.

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