A copper rod of $88\,\text{cm}$ and an aluminum rod of unknown length have their increase in length independent of increase in temperature. The length of aluminum rod is ($\alpha_{\text{Cu}} = 1.7 \times 10^{-5}\,\text{K}^{-1}$ and $\alpha_{\text{Al}} = 2.2 \times 10^{-5}\,\text{K}^{-1}$)