There are two metallic wires of the same thickness made from iron and silver. If the length of iron wire is 12cm, what should be the length of silver wire which is equal to the resistance of iron wire? Data : Resistivity of iron ` = 10 xx 10^(-8) Omega m`
Resistivity of silver ` = 16 xx 10^(-8) Omega m`

Explanation

`I_(i) = 12 cm `
`I_(s) = ? `
` S_(i) = 10 xx 10^(-8) Omega m `
` S_(s) = 16 xx 10^(-8) Omega m`
` (S_i)/(S_(s) ) = (I_s)/(I_i) = (10 xx 10^(-8) )/(16 xx 10^(-8) ) = (I_((s)) )/(12) = 120/16 = I_((s)) `
`I_((s)) = 7.5 cm`