Physics Question from JEE Main 2025 · 22 January, Shift 1

Three conductors of same length having thermal conductivity $k_1$, $k_2$, and $k_3$ are connected as shown in figure. Area of cross sections of 1st and 2nd conductor are same and for 3rd conductor it is double of the 1st conductor. The temperatures are given in the figure. In steady state condition, the value of $\theta$ is _____ $^\circ\text{C}$. (Given: $k_1$ = $60 \, \text{Js}^{-1}\text{m}^{-1}\text{K}^{-1}$, $k_2$ = $120 \, \text{Js}^{-1}\text{m}^{-1}\text{K}^{-1}$, $k_3$ = $135 \, \text{Js}^{-1}\text{m}^{-1}\text{K}^{-1}$)