Equal temperature difference exists between the ends of two metallic rods 1 and 2 of equal length. Their thermal conductivities are K1 and K2 and cross-sectional areas are respectively A1 and A2 The condition for equal rate of heat transfer will be
The rate of flow of heat is given by
Since [T1 - T2) and / are the same for two rods, the rate of flow of heat will be the same, if