A steel scale measures the length of a copper wire as $80.0\, cm$, when both are at $20^{\circ} C$, the calibration temperature for the scale. What would the scale read for the length of the rod when both are at $40^{\circ} C ?$
Given: $\alpha$ for steel $=11 \times 10^{-6}$ per ${ }^{\circ} C$ and $\alpha$ for $Cu =11 \times 10^{-6} \text{per} ^{\circ} C$