Question

A unit scale is to be prepared whose length does not change with temperature and remains $20\, cm$, using a bimetallic strip made of brass and iron each of different length The length of both components would change in such a way that difference between their lengths remains constant If length of brass is $40 \,cm$ and length of iron will be ________cm$$(\alpha_{iron}=1.2\times10^{-5}K^{-1} \,\,\,and \,\,\,\alpha_{brass}=1.8\times10^{-5}K^{-1}).

Answer 1

The correct answer is 60