Question

Four rods of same material but different radii r and length l are used to connect two reservoirs of heat at different temperatures the one which will conduct most heat is

Answer 1

Given Four rods of same material but different radii r and length l are used to connect two reservoirs of heat at different temperatures the one which will conduct most heat is

Here the rate of heat transfer r^2 is directly proportional to 1 / l

 So q / t ∝ r^2 / l

So dq / dt is directly proportional to r / l

If dq / dt increases, then a / l also increases.

The rod whose  a / l ratio is more, will conduct most heat or conduct more amount of heat.