Two thin metal strips, one of brass and the other of iron are fastened 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 arc formed by the bimetallic strip when heated to 80°C is (Coefficient of linear expansion of brass = 19 × 10-6/°C & of iron = 12 × 10-6/°C).