The temperature difference across two cylindrical rods A and B of same material and same mass are 40 °C and 60 °C respectively. In steady state, if the rates of flow of heat through the rods A and B are in the ratio 3 : 8, the ratio of the lengths of the rods A and B is
1
1 : 3
2
5 : 3
3
4 : 3
4
2 : 3