A composite cylinder is made of two materials having thermal conductivities `K_(1)` and `K_(2)` as shown. Temperature of the two flat faces of cylinder are maintained at `T_(1)` and `T_(2)`. For what ratio `K_(1)//K_(2)` the heat current throught the two materials will be same. Assume steady state and the rod is lagged (insulated from the curved surface).

Three rods of the same dimension have thermal conductivity 3K, 2K and K as shown in the figure. The temperature of the junction in steady-state is

Two identical rods are made of different materials whose thermal conductivities are K_(1) and K_(2) . They are placed end to end between two heat reservoirs at temperatures theta_(1) and theta_(2) . The temperature of the junction of the rod is

A slab consists of two parallel layers of two different materials of same thickness having thermal conductivities K_(1) and K_(2) . The equivalent conductivity of the combination is

A slab consists of two layers of different materials of the same thickness and having thermal conductivities K_(1) and K_(2) . The equivalent thermal conductivity of the slab is

Two walls of thicknes l_(1) and l_(2) and ther-mal condctivities K_(1) and K_(2) are in contact In the steady state, if the temperature at the outer faces are T_(1) and T_(2) find the temperature at the common wall .

Two rods of the same length and diameter, having thermal conductivities K_(1) and K_(2) , are joined in parallel. The equivalent thermal conductivity to the combinationk is

A rod of length l and cross-section area A has a variable thermal conductivity given by K = alpha T, where alpha is a positive constant and T is temperature in kelvin. Two ends of the rod are maintained at temperature T_(1) and T_(2) (T_(1)gtT_(2)) . Heat current flowing through the rod will be

A composite spherical shell is made up to two materials having thermal conductivities k and 2k respectively as shown in the diagram . The temperature at the innermost surface is maintained at T whereas the temperature at the outermost surface is maintained at 10 T . A, B, C and D are four points in the outer material such that AB = BC = CD. The effective thermal resistance between the inner surface of the shell and the outer surface of the shell for the radial heat flow is

Three rods of same dimensions have thermal condutivity 3K,2K and K They are arranged as shown in Then the temperature of the junction in steady state is .