Given: height \(=10 cm\),
breadth \(=10 cm\)
thickness \(L=25 cm =0.25 m\)
rate of heat exchange \(q=1000 W\)
\(T_{2}=27^{\circ} C , T_{1}=?\)
coefficient of thermal conductivity
\(k=0.0541 Wm ^{-1} k ^{-1}\)
correlating equation - One dimensional conduction heat equation (Fourier law) i.e.
$$
\begin{aligned}
&q=\frac{K A(\Delta T)}{L}=\frac{K A\left(T_{\text {hot }}-T_{\text {cool }}\right)}{L} \\
&\frac{Q L}{K A}=T_{1}-T_{2} \\
&\frac{1000 \times 0.25}{0.0541 \times 10 \times 10}=T_{\text {hot }}-T_{\text {cool }} \\
&46.21=T_{1}-T_{2} \\
&T_{1}=46.21+27=73.3^{\circ} C
\end{aligned}
$$