The ratio of thermal conductivity of two rods of different materials is 4:3 . The two rods have same area of cross-section and same thermal resistance. The lengths of rods are in the ratio

Step-by-step solution

Thermal resistance is given by R = L KA . Given that the thermal resistances are equal ( R₁ = R₂ ) and the areas of cross-section are equal ( A₁ = A₂ ), we have: L₁ K₁ A = L₂ K₂ A L₁ L₂ = K₁ K₂ Given the ratio of thermal conductivities K₁ : K₂ = 4 : 3 , we get: L₁ L₂ = 4 3 The lengths of the rods are in the ratio 4 : 3 . Answer: 4 : 3