Two rods of same length and areas of cross section `A_1` and `A_2` have their ends at same temperature. If `K_1` and `K_2` are their thermal conductivities, `C_1` and `C_2` their specific heats and `rho_1` and `rho_2` are their densities, then the condition that rate of flow of heat is same in both the rods is

Options

A. `A_(1)//A_(2)=K_(1)//K_(2)`
B. `A_(1)//A_(2)=K_(1)C_(1)rho_(1)//K_(2) C_(2)rho_(2)`
C. `A_(1)//A_(2)=K_(2)C_(1)rho_(1)//K_(1)C_(2)rho_(2)`
D. `A_(1)//A_(2)=K_(2)//K_(1)`

Answer

D

Explanation

`L/(K_(1)A_(1))=L/(K_(2)A_(2))`