A negligibly small current is passed through a wire of length 15 m and 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 ?

Explanation

Length of the wire, `l = 15` m
Area of the cross-section of the wire, `a = 6.0 xx 10^(-7) m^(2)`
Resistance of the material of the wire, `R = 5.0 Omega`
Resistivity of the material of the wire `= rho`
Resistance is related with the resistivity as
`R = rho (l)/(A)`
`rho = (RA)/(l)`
`= (5 xx 6 xx 10^(-7))/(15) = 2 xx 10^(-7) Omega` m
Therefore, the resistivity of the material is `2 xx 10^(-7) Omega` m.