Two thin metal strips, one of brass and the other of iron are fastened together parallel to each other, a distance 1mm apart to form a bimetallic strip. If the strips are of equal length at 0⁰C . The radius of the arc formed by the bimetallic strip when heated to 60⁰C is (Coefficient of linear expansion of brass$=19\times {10}^{-6} {/}^0\mathrm{C}$ and of iron$=12\times {10}^{-6} {/}^0\mathrm{C}$