Q 11-10-043NEETJEE MainEasy
Two rods of the same material and length have radii in the ratio $1 : 2$. With the same temperature difference across their ends, the ratio of their rates of heat flow is
Answer: (B) $1 : 4$
$\dfrac{Q}{t} = \dfrac{KA\Delta\theta}{l} \propto A \propto r^2$, so the ratio is $1 : 4$.
Solution by Sreeraj P, M.Sc Physics