Question

Six identical metallic rods are joined together in a pattern as shown in the figure. Points $A$ and $D$ are maintained at temperatures $60^{\circ}C$ and $240^{\circ}C$. The temperature of the junction $B$ will be

• A. $ 120^{\circ} C $
• B. $ 150^{\circ }C $
• C. $ 60^{\circ} C $
• D. $ 80^{\circ} C $

Answer 1

Answer: (A)

Equivalent eiectrical circuit will be as shown in the figure
Temperature difference between $A$ and $D$ is $180^{\circ} C$,
which is equally distributed in all the rods.
Therefore, temperature different between $C$ and $D$ will be $60^{\circ} C$ or temperature of $C$ should be $=180^{\circ}$
So, the temperature at junction $B$
$180^{\circ}-\theta=\theta-60^{\circ} $
$\theta=120^{\circ} C$