Question

The mean distance between the atoms of iron is $3 \times 10^{-10}$ $m$ and interatomic force constant for iron is $7 N / m$. The Young's modulus of elasticity for iron is

• A. $2.33 \times 10^{5} N / m ^{2}$
• B. $23.3 \times 10^{10} N / m ^{2}$
• C. $2.33 \times 10^{9} N / m ^{2}$
• D. $2.33 \times 10^{10} N / m ^{2}$

Answer 1

Answer: (D)

Given, $r_{0}=3 \times 10^{-10} \,m , k=7 \,N / m$
As $k=Y r_{0}$
$\therefore Y=\frac{k}{r_{0}}$
$=\frac{7}{3 \times 10^{-10}}$
$=2.33 \times 10^{10} \,N / m ^{2}$