Two ends of rods of length L and radius R of the same material of kept at the same temperature. Which of the following rods conducts the maximum heat?

Two ends of rods of length Land radius r of the same material are kept at the same temperature. Which of the following rods the same material are kept at the same temperature. Which of the following rods conducts most heat in a given time interval

Which of the following circular rods (given radius r length x and each made of the same material) whose ends are maintained at the same temperature will conduct most heat?

Which of the following circular rods, (given radius r and length l) each made of the same material and whose ends are maintained at the same temperature will conduct most heat?

Which of the following circular rods (given radius r and length l ) each made of the same material and whose ends are maintained at the same temperature will conduct most heat?

Which of the following circular rods (given radius r and length l ) each made of the same material and whose ends are maintained at the same temperature will conduct most heat?

Which of the following circular rods. (given radius r and length l ) each made of the same material as whose ends are maintained at the same temperature will conduct most heat

Four rods of same material with different radii r and length l are used to connect two reservoirs of heat at different temperatures. Which one will conduct maximum heat?

Two unifrom brass rod A and B of length l and 2l and radii 2r respectively are heated to the same temperature. The ratio of the increase in the volume of A to that of B is