(a) At what temperature would the resistance of a copper conductor be double of its value of `0^(@)C`? (b) Does this same temperature hold for all copper conductors, regardless of shape and size? `[alpha_(c) = 4.0xx10^(-3).^(@)C^(-1)]`

Explanation

(a) `R_theta = R_0[1 + alpha(theta - 0)]`
`2 R_0 = R_0[1 + alpha theta]`
`theta = (1)/(alpha) = (1)/(4 xx 10^-3) = 250^(@)C`
(b) As `theta = 1//alpha, theta` is independent of length / and area of cross-section, it is valid for all copper conductors.