Question

A force of $30N$ acts on a rod of area of cross section 5 x 10${}^{-6}$ $m^2$. The stress produced in dyne/cm${}^2$ is :

• A. $6\times 10$${}^6$
• B. $6\times 10$${}^7$
• C. $6\times 10$${}^5$
• D. $0.16\times 10$${}^{-6}$

Answer 1

The correct option is B $6\times 10$${}^7$

$1N={10}^{5}dyne$

$stress=\frac{30\times {10}^{5}dyne}{5\times {10}^{-6}\times {10}^{4}c{m}^2}$

$=6\times {10}^{7}dyne/c{m}^2$