Two thin metal strips, one of brass and the other of iron are fastended together parallel to each other. Thickness of each strip is `2 mm`. If the strips are of equal length at `0^(@)C`. The radius of the are formed by the bimetaalic strip when heated to `80^(@)C` is (Coefficient of linear expansion of brass`=19xx10^(-6)//^(@)C &`
of iron=`12xx10^(-6)//^(@)C)`.

Options

A. `3.57m`
B. `2.67m`
C. `3.12m`
D. `4.56m`

Answer

A

Explanation

`r=(2t)/((alpha_(1)-alpha_(2))DeltaT)`