Q.
Three rods made of same material and having same cross-section are joined as shown in the figure. Each rod is of same length. The temperature at the junction of the three rods is
A) 45$℃$
B) 90$℃$
C) 30$℃$
D) 60$℃$
Explanation
(d) Let the temperature of function be $\theta$, then
$H = H_{1} + H_{2}$
$\Rightarrow$ $\frac{KA(\theta - 0)}{L} = \frac{KA(90 - \theta)}{L} + \frac{KA(90 - \theta)}{L}$
[image:11_image68.emf]
Or $\theta = 90 - \theta + 90 - \theta$
Or $\theta = 180 - 2\theta$
Or $3\theta = 180$
Or $\theta = 60℃$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.