A unit scale is to be prepared whose length dows not change with temperature and remains 20cm, using a bimetallic strip made of bass and iron each of different length. The length of both components would change in such a way that difference between their length remains constant. If length of brass is 40cm and length of iron will be ________cm.

$(α_{i r o n} = 1.2 \times 1 0^{- 5} K^{- 1} a n d α_{b r a s s} = 1.8 \times 1 0^{- 5} K^{- 1}) .$

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Vishal Baghel | Contributor-Level 10

2 months ago

$l_{B} (1 + α_{B} Δ T) - l i (1 + α_{i} Δ T) = l_{B} - l_{i}$

$\Rightarrow α_{B} l_{B} = l_{i} α_{i}$

$l_{i} = 60 c m$

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