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A bird sitting on a single high tension wire does not get electrocuted because

A) the circuit is not complete

B) the bird feet has an insulating covering.

C) capacitance of the bird is too small and the line frequency is too small.

D) resistance of the bird is too high.

This question is from kvpy exam that was held on 5th November, the official answer key says its (c) but thats tentative. Could someone please explain this?

I know this kinda questions dont go too well on stackexchange but this question has us intrigued as everyone expected the answer would be (a) or (d)

Emilio Pisanty
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Hari07
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2 Answers2

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Badly stated question.

If the capacitance is high and the frequency high, assuming one is talking of an AC high tension,the alternating fields will cook the bird, ( like a microwave oven) .

BUT powerlines are not made with such conditions because a lot of energy would be lost in ionizing the air. For existing power lines the answer is A, the circuit is not complete.

anna v
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I think the question itself is quite bad for an exam because:

A) the circuit is not complete: This is true depending on what you mean with complete.

B) the bird feet has an insulating covering. This is also true, partially, most animals skin is dry and insulate a lot better than flesh. This helps in all cases both for a complete circuit than for a simple "capacitor to air" circuit.

C) capacitance of the bird is too small and the line frequency is too small. This is also true.

D) resistance of the bird is too high. This is "less" true, but since B is true this is partially true.

B and D highly depends on the voltage of the line.

fededevi
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