Question

S.I unit for the coefficient of viscosity is equal to?

• A. $N{m}^{-1}s$
• B. $Pa{s}^{-1}$
• C. $N{m}^{-2}s$
• D. $Pa{s}^{-2}$

Answer 1

The correct option is C $N{m}^{-2}s$

$\begin{array}{c}\text{we know that}\\ \text{coefficiont of}V\text{iscosity}=\frac{F}{A\left(dv/dx\right)}\\ \text{where}f=\text{force}A=\text{area}\\ v=velocityx=\text{distance}\\ \text{so si unit is}\end{array}$

$\frac{N}{(m{)}^2\left[\frac{ms}{m}\right]}=\frac{kgm{s}^{-2}}{(m{)}^2\left[\frac{m{s}^{-1}}{m}\right)}=\mathrm{kg}{m}^{-1}{s}^{-1}=N{m}^{-2}s$