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Wheatstone bridge principal is used to measure of specific resistance (S 1 ) of given wire, having length L, radius r. If X is the resistance of wire, then specific resistance is ; S 1 = X ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ π L r 2 . If the length of the wire gets doubled, then the value of specific resistance will be

1. S 1
2. 2 S 1
3. 4 S 1
4. 2S 1

Correct answer: S 1

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