A negligibly small current is passes through a wire of length `15 m` and of uniform cross-section `6.0 xx 10%-7 m^2` and its resistance is measured to be `5.0 Omega`. What is the resistivity of the material at the temperature of the experiment ?

Answer

`2.0 xx 10^-7 ohm m`

Explanation

As `R = rho (l)/(A), rho = (RA)/(l) = ((5.0 Omega)(6.0 xx 10^-7 cm^2))/(15 cm) = 2.0 xx 10^-7 Omega m`.