Question

The space of 20 mm between the two parallel vertical plates is filled with the oil of viscosity 2 N s/m². Determine the shear stress in oil if one plate is displaced with a velocity of 1 m/s
1. 100 N/m²
2. 150 N/m²​
3. 200 N/m²​
4. 50 N/m²​

Answer 1

Correct Answer - Option 1 : 100 N/m²

Concept:

The shear stress in oil if one plate is displaced with a certain velocity is given by,

\(\tau = \mu \frac{V}{{{h_o}}}\)

Where μ = Coefficient of the viscosity of the oil, V = velocity of the moving plate, ho = the clearance between the plates

Calculation:

Given:

μ = 2 N s/m2 , V = 1 m/s, ho = 20 mm = 0.020 m

\(\tau = \frac{{\mu}V}{{{h_o}}} = \frac{2\times1}{0.020} = 100\; N/m^2\)