Question

What is the SI unit of viscosity?
1. Poiseiulle
2. Pascal/second
3. Newton-Second
4. Newton/Second

Answer 1

Correct Answer - Option 1 : Poiseiulle

The correct answer is Poiseiulle.

• Viscosity is a measure of resistance to flow which arises due to the internal friction between layers of fluid.
• This resistance to fluid motion is like internal friction analogous to friction when a solid moves on a surface.
• Strong intermolecular forces between molecules hold them together and resist the movement of layers past one another.
• The SI unit of viscosity is poiseiulle (Pl), named after the scientist Jean Louise Poiseuille.
• Its other units are N s m^-2 or Pa s.
• The dimensions of viscosity are [ML^-1T^-1].
• 1 poise = 1 g cm–1s–1 = 10–1kg m–1s–1.

• The product of force and time is called impulse, which is the change in momentum.
• Newton-Second is the derived unit of Impulse.