Two thin metal strips each of 2mm thick, one of brass and the other of iron are fastened   together  parallel to each other, to form  a bimetallic strip. If the strips are  of equal  length  at 0°c . The radius of the arc  formed  by the  bimetallic strip when heated to C is (Coefficient of linear expansion of brass =  19×10−6/∘C  and of iron = 12×10−6/∘C )