Thermal Properties of Matter

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