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Question
Resistance of a metal wire of length 5 m is 100 Ω . If the area of cross - section of the wire is `3 × 10^-7 "m"^2` , Calculate the resistivity of the metal .
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Solution
R = 100 Ω
l = 5m
`A = 3 xx 10^-7 "m"^2`
`K = (rho l)/A` ⇒ `therefore rho = (RA)/l`
`δ = (100 xx 3 xx 10^-7)/5 = 60 xx 10^-7`
= `6 xx 10^-6 Omega-m`
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