A uniform wire of resistance 100Ω is melted

CBSE Class 10 CBSE Class 10 Science
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1

A uniform wire of resistance 100Ω is melted and recast into wire of length double that of the original. What would be the resistance of the new wire formed?

2

Given R = 100 Ω
When 'l = 'l, R = 100$\Omega$
When 'l = 2l’
R = pl/A
====> R = p(2l)/A
=====> R = 2(pl/A) ===> 'R = 2R’
Resistance is doubled.
R = 2 X 100 Ω = 200 Ω