A steel wire of length 20 cm and uniform cross-section `1mm^(2)` is tied rigidly at both the ends. If the temperature of the wire is altered from `40^(@)C` to `20^(@)C`, the change in tension. [Given coefficient of linear expansion of steel is `1.1xx10^(5) .^(@)C^(-1)` and Young's modulus for steel is `2.0xx10^(11) Nm^(-2)`]

Explanation

To find the change in tension in the steel wire when the temperature is altered, we can follow these steps:

### Step 1: Understand the Problem
We have a steel wire of length \( L_0 = 20 \, \text{cm} = 0.2 \, \text{m} \) and a uniform cross-section of \( A = 1 \, \text{mm}^2 = 1 \times 10^{-6} \, \text{m}^2 \). The temperature changes from \( 40^\circ C \) to \( 20^\circ C \). We need to calculate the change in tension due to this temperature change.

### Step 2: Calculate the Change in Temperature
The change in temperature \( \Delta \theta \) is given by:
\[
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