The resistances of a copper wire and an iron wire at are and

PHYSICS · Subjective · CBSE · Physics · Current Electricity · Current Electricity

Problem

The resistances of a copper wire and an iron wire at

20^\circ\mathrm{C}

are

4.1\,\Omega

and

3.9\,\Omega

, respectively. Neglecting thermal expansion, find the temperature at which the resistances of both are equal. Given

\alpha_{\mathrm{Cu}}=4.0\times10^{-3}\,\mathrm{K^{-1}}

and

\alpha_{\mathrm{Fe}}=5.0\times10^{-3}\,\mathrm{K^{-1}}