Question

The surface tension of a liquid is $70\text{dyne/cm}$. In MKS system its value is

• A. $70\text{N/m}$
• B. $7\times {10}^{-2}\text{N/m}$
• C. $7\times {10}^2\text{N/m}$
• D. $7\times {10}^3\text{N/m}$

Answer 1

The correct option is B $7\times {10}^{-2}\text{N/m}$

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

$\therefore 70dyne/cm=\frac{70\times {10}^{-5}N}{{10}^{-2}m}=7\times {10}^{-2}N/m$