Four identical rods of same material are joined end to end to form a square. If the temperature difference between the ends of a diagonal is 100∘ C , then the temperature difference between the ends of other diagonal will be
0∘C
Suppose temperature difference between A and B is 100∘C and θA>θB
Heat current will flow from A to B via path ACB and ADB. Since all the rod are identical so Δθ)AC=(Δθ)AD
(Because heat current H=ΔθR ; here R = same for all.)
⇒θA−θC=θA−θD⇒θC=θD
i.e. temperature difference between C and D will be zero.