Find the expression for heat conducted (q) through a slab thickness (L), cross sectional area (A) having temperature T1and T2 at both ends for steady state. The inner surface of a plane brick wall is...

Find the expression for heat conducted (q) through a slab thickness (L), cross sectional area (A) having temperature T1and T2 at both ends for steady state.

The inner surface of a plane brick wall is at 60°C and outer surface is at 35°C. Calculate the rate of heat transfer per sq metre surface area of the wall which is 220 mm thick. Thermal conductivity of the brick is 0.51 W/mk.