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Question
A 10 m long wire of a particular material is of resistance 5Ω What will be the resistance if the wire is stretched to double its length?
Solution
On stretching the wire to double its length, the length is doubled and its area of cross-section is reduced to half. So the resistance becomes four times i.e. the resistance of wire will become: 4 × 5Ω = 20 Ω.
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