Chill Out and Conquer the Refrigeration Operator Test 2026 – Your Cool Career Starts Here!

To determine the new length of the steel bar when it is heated, we can use the concept of thermal expansion. When materials are heated, they expand, and this can be quantified using the linear expansion formula:

\[

\Delta L = L_0 \times \alpha \times \Delta T

\]

Where:

- \(\Delta L\) is the change in length,

- \(L_0\) is the original length (25m in this case),

- \(\alpha\) is the thermal expansion coefficient for steel (approximately \(12 \times 10^{-6} \, \text{°C}^{-1}\)),

- \(\Delta T\) is the change in temperature (from 30 °C to 100 °C, which is a change of 70 °C).

Using this formula, we calculate the change in length:

\[

\Delta L = 25 \, \text{m} \times (12 \times 10^{-6} \, \text{°C}^{-1}) \times (70 \, \text{°C})

\]

\[

\Delta L = 25 \times 12 \times 70 \times 10^{-6