Fluid Properties MCQ with answer and solution

Concept

SI unit of dynamic viscosity

Formula

μ = τ / (du/dy); 1 Pa·s = 1 N·s/m² = 10 poise

Step-by-step solution

1. μ = shear stress / velocity gradient = (N/m²) / (1/s) = N·s/m². 2. N/m² = Pa, so the unit is also Pa·s.

Explanation

The SI unit of dynamic viscosity is the pascal second, which is the same as newton second per square metre. N/m² is the unit of pressure or stress.

Shortcut

1 Pa·s = 1 N·s/m² = 10 poise.

Common mistake

Choosing a single option when two are equal.