A composite cylinder consists of $100$ mm radius steel pipe of $25$ mmthickness over which two layers of insulation $30$ mm and $35$ mm arelaid. The conductivities are $25$ W$/$mK$,0\mathrm{.}25$ W$/$mK and $0\mathrm{.}65$ W$/$mK$.$The inside is exposed to convection at $300\backslash$deg C with h $=65$ W$/$m$2$K$.$ Theoutside is exposed to air at $30\backslash$deg C with h $=15$ W$/$m$2$K$.$ Determine theheat loss per meter length. Also find the interface temperatures.