Question

The maximum elongation of a steel wire of 1 m length if the elastic limit of steel and its Young’s modulus, respectively, are 8 × 108 N m–2 and 2 × 1011 N m–2, is :

• A. 4 mm
• B. 0.4 mm
• C. 40 mm
• D. 8 mm

Answer 1

Answer: (A)

4 mm

Answer 2

Maximum elongation is calculated using$\Delta L = \frac{\sigma L}{Y}$. Substituting values:
$\Delta L = \frac{8 \times 10^8 \times 1}{2 \times 10^{11}} = 4 \, mm$.