Question

At which temperature the resistance of a copper wire will be double of the resistance at $0^{o}C$ ? (Resistance temperature coefficient is $4.0\times {10}^{-3}{}^0{C}^{-1}$) ?

Answer 1

$R=R_0\left(1+\alpha \left(T-T_0\right)\right)$

$=2R_0=R_0\left(1+\alpha \left(T-0\right)\right)$

$=2=1+\alpha \left(T-0\right)$

$=1=\alpha T$

$=\frac{1}{4\times {10}^{-30}}=\frac{100}{4}\times {10}^{28}$

$=25\times {10}^{28}{}^{0}C$

We get$,$

$=25\times {10}^{28}{}^{0}C$