Question

In determination of young modulus of elasticity of wire, a force is applied and extension is recorded. Initial length of wire is '1 m'. The curve between extension and stress is depicted then Young's modulus of wire will be K $\times$ ${10}^9$ $\frac{N}{m^2}$, where K is .

Answer 1

We know that,

Youngs modulus = Y = $\frac{Sress}{Strain}$

$⟹Y=\frac{\frac{F}{A}}{\frac{\Delta l}{l}}$

$Y=\frac{4000\times {10}^3}{\frac{2\times {10}^{-3}}{1}}$
$Y=\frac{4000\times {10}^3}{2\times {10}^{-3}}=2\times {10}^9\frac{N}{m^2}$.

Thus, K = 2.