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?

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