Step 1: Use the heat conduction formula.
The heat flow \( Q \) through a rod is given by Fourierâs Law:
\[
Q = \frac{k A \Delta T}{L}
\]
where:
- \( k \) is the coefficient of thermal conductivity,
- \( A \) is the cross-sectional area,
- \( \Delta T \) is the temperature difference, and
- \( L \) is the length of the rod.
Step 2: Calculate the Temperature Gradient.
The temperature gradient is given by:
\[
\text{Temperature Gradient} = \frac{\Delta T}{L}
\]
Substitute the given values:
\[
\Delta T = 125^\circ C - 25^\circ C = 100^\circ C
\]
\[
L = 50 \, \text{cm} = 0.5 \, \text{m}
\]
Thus, the temperature gradient is:
\[
\text{Temperature Gradient} = \frac{100}{50} = 2 \, \text{°C/cm}
\]