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A uniform metallic wire is elongated by 0.04 m when subjected to a linear force F. The elongation, if its length and diameter are doubled and subjected to the same force will be ____ cm.

1. 0.04
2. 0.08
3. 0.16
4. 0.02

Correct answer: 0.02

Solution

Elongation = FL/(A*Y). Doubling length multiplies by 2; doubling diameter quadruples area, dividing by 4. Net factor 2/4 = 1/2, so new elongation = 0.04/2 = 0.02.

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