A wire of resistance 4 Ohms is stretched to double its ... – Physics

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A wire of resistance 4 Ohms is stretched to double its length. What is its new resistance?

A8 Ohms

B16 Ohms

C2 Ohms

D4 Ohms

✓ Correct Answer: B — 16 Ohms

When length doubles (L'=2L), the area halves (A'=A/2) because volume is constant. New R' = ρ(2L)/(A/2) = 4R = 4*4 = 16 Ohms.

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