The two ends of a rod of length L and a uniform cross-sectional area A are kept at two temperatures T1 and T2 (T1 > T2 ). The rate of heat transfer, dQ/dt through the rod in a steady state is given by:

\(\frac{dQ}{dt} = \frac{k(T_1-T_2)}{AL}\) \(\frac{dQ}{dt} = ALk(T_1-T_2)\) \(\frac{dQ}{dt} = \frac{kA(T_1-T_2)}{L}\) \(\frac{dQ}{dt} = \frac{kL(T_1-T_2)}{A}\)

\(\frac{dQ}{dt} = \frac{kA(T_1-T_2)}{L}\)

In steady state \(\frac{dQ}{dt} = \frac{kA(T_1-T_2)}{L}\)