Question

$SI$ unit of coefficient of viscosity is

• A. $Ns{m}^{-2}$
• B. $N{s}^{-1}{m}^2$
• C. $Ns{m}^{-3}$
• D. $N{s}^{-2}m$

Answer 1

Answer: (A)

We know that, Viscous force,
$F=-\eta A\frac{dv}{dx}$
or $\eta =-\frac{F}{A.\frac{dv}{dx}}$ Thus, unit is ${\text{N s m}}^{-2}$