Question

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 ${100}^{\circ }$ C , then the temperature difference between the ends of other diagonal will be

• A.
• B. ; where l is the length of each rod
• C.
• D.

Answer 1

The correct option is A

Suppose temperature difference between A and B is ${100}^{\circ }C$ and ${\theta }_A>{\theta }_B$

Heat current will flow from A to B via path ACB and ADB. Since all the rod are identical so $\Delta \theta {)}_{AC}=(\Delta \theta {)}_{AD}$
(Because heat current $H=\frac{\Delta \theta }{R}$ ; here R = same for all.)
$\Rightarrow {\theta }_A-{\theta }_C={\theta }_A-{\theta }_D\Rightarrow {\theta }_C={\theta }_D$
i.e. temperature difference between C and D will be zero.