Question

At what temperature the resistance of a copper wire will become three times of its value at 0 degree celcius

Answer 1

you didn't mention about temperature coefficient of copper , $\alpha$.

well, it is an experimental value. we can get it in another source.

e.g., temperature coefficient of copper, $\alpha$ = 0.00386/°C

we know, the relation between temperature and resistance,

$R_t=R_0(1+\alpha\Delta T)$,

where $R_t$ Resistance at temperature t, $R_0$ is initial resistance of substance and ∆T is change in temperature.

here, $R_t=3R_0$ , ∆T = (t - 0)=t and $\alpha$ = 0.00386/°C

so, 3 = 1 + 0.00386 × t

or, 2 = 0.00386 × t

or, 1/0.00193 = t

or, t = 100000/193 = 518.13°C