A wire `1.0` m long, `0.2` mm in diameter, has a resistance of `10 Omega`. Calculate the resistivity of its material.

Explanation

Here , `l = 1.0 m, r = (0.2 mm)/(2) = 0.2 mm = 10^-4 m R = 10 Omega`
As `R = (rho l)/(A), rho = (RA)/(l) = ((10 Omega) [3.14 xx 10^-8 m^2])/(1.0 m) = 3.14 xx 10^-7 Omega m`
`[as A = pi r^2 = 3.14 xx (10^-4 m)^2 = 3.14 xx 10^-8 m^2]`.