What will be the length of a nichrome wire resistance 5.0Ω, if the length of similar wire of 120 cm has resistance of 2.5 Ω? Why?

Here,


2 = 120cm = 1.20m


R1 = 5.0Ω


R2 = 2.5Ω


Now,



And



(Here, resistivity and the area A remain same as the wires are similar.)




Now,



l1 = 2×120×10-2 m


l1 = 24×10-1 m


∴ l1 = 240 cm


16