A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature. The length of…

A copper rod of $\displaystyle 88$ cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature. The length of aluminium rod is : $\displaystyle \left(\alpha_{\mathrm{Cu}}=1.7 \times 10^{-5} \mathrm{~K}^{-1}\right.$ and $\displaystyle \alpha_{\mathrm{Al}}=2.2 \times 10^{-5} \mathrm{~K}^{-1}$ )