A composite rod is made by joining a copper rod, end to end, with a second rod of a different material but of same cross-section. At `25^(@)C`, the composite rod is 1 m in length of which the length of the copper rod is 30 cm. At `125^(@)C` the length of the composite rod increases by 1.91 mm. The coefficient of linear expansion of copper is `alpha=1.7 times 10^(-5@)C^(-1)` and that of the second rod is `beta=n times 10^(-5@)C^(-1)`. Find the value of n.

Answer

2