Why springs are made up of steels and not copper commonly ?

Options

A. Copper is costlier than steel
B. Copper is more elastic than steel
C. Steel is more elastic than copper
D. None of the above

Explanation

To understand why springs are commonly made of steel rather than copper, we can analyze the properties of elasticity and the Young's modulus of both materials.

### Step-by-Step Solution:

1. **Understanding Young's Modulus**:
Young's modulus (Y) is a measure of the stiffness of a material. It is defined as the ratio of stress (force per unit area) to strain (deformation in length/original length). The formula is given by:
\[ Y = \frac{F/A}{\Delta L/L_0} \]
where:
- \( F \) = force applied
- \( A \) = cross-sectional area
- \( \Delta L \) = change in length
- \( L_0 \) = original length

2. **Comparing Young's Modulus of Steel and Copper**:
- Steel has a higher Young's modulus compared to copper. This means that for the same amount of stress applied, steel will deform (elongate) less than copper.
- A higher Young's modulus indicates that the material is stiffer and can withstand greater forces without deforming significantly.

3. **Implications for Springs**:
- Springs are designed to return to their original shape after being stretched or compressed. If a spring material has a high Young's modulus, it will be able to return to its original shape more effectively after the force is removed.
- Since steel has a higher Young's modulus than copper, it is more suitable for making springs. This means that steel springs can handle more load and will not stretch as much under the same conditions compared to copper springs.

4. **Conclusion**:
- Therefore, springs are made of steel and not copper because steel is more elastic (higher Young's modulus) than copper, which results in less elongation under the same load, making steel springs more efficient and durable.