1. Two rods one made of copper and other made of steel of the samelength and same cross sectional area are joined together. The thermal conductivity of copper and steel are 385Js⁻¹K⁻¹m⁻¹ and 50Js⁻¹K⁻¹m⁻¹ respectively. The free ends of copper and steel are held at \(100^\circ C\) and \(0^\circ C\) respectively. The temperature at the junction is, nearly: