Question

A conductor has resistance of $15\Omega$ at ${10}^{o}C$ and $18\Omega$ at ${400}^{o}C$. Find temperature coefficient of resistance of the material.

Answer 1

Given : $R_2=18\Omega$ $T_2={400}^{o}C$ $R_1=15\Omega$ $T_1={10}^{o}C$

Change in temperature $\Delta T=400-10={390}^{o}C$

Using $R_2=R_1(1+\alpha \Delta T)$

Or $18=15(1+\alpha \times 390)$

$⟹\alpha =5.1\times {10}^{-4}{/}^{o}C$