Question

The shear stress at a point in a liquid is found to be $0.03N/m^2$. If the velocity gradient at the point is $0.15s^{-1}$, what will be it is viscosity (in poise)?

• A. 20
• B. 2
• C. 0.2
• D. 0.5

Answer 1

The correct option is B 2

$\tau =\mu \left(\frac{du}{dt}\right)$
$\mu =$ coefficient of viscosity
$\frac{du}{dx}=$ velocity gradient

$\tau$ = Shear stress
$\mu =-\frac{\tau }{\left(\frac{du}{dt}\right)}=\frac{0.03}{0.15}$
$\mu =2$ poise