Identify the correct unit(s) of dynamic viscosity (absolute viscosity). Which of the following correctly represents dynamic viscosity in the CGS system?

Introduction / Context:
Viscosity units are frequently encountered in fluid mechanics, rheology, and transport phenomena. Distinguishing dynamic viscosity (μ) from kinematic viscosity (ν) and matching the correct unit system prevents serious calculation errors.

Given Data / Assumptions:

• Dynamic viscosity μ measures shear stress per unit velocity gradient.
• CGS units are commonly used alongside SI in older literature.
• We compare the options with known unit definitions.

Concept / Approach:
In CGS, dynamic viscosity is measured in poise (P), where 1 P = 1 g/(cm·s). Kinematic viscosity is measured in stokes (St), where 1 St = 1 cm^2/s. In SI, μ uses Pa·s or N·s/m^2 equivalently.

Step-by-Step Solution:

Verification / Alternative check:
Convert between SI and CGS: 1 Pa·s = 10 P. This cross-check helps align SI values with CGS references when required.

Why Other Options Are Wrong:

• Stoke: This is for kinematic viscosity, not dynamic viscosity.

Common Pitfalls:
Confusing ν with μ; remember ν = μ/ρ. Using the wrong property unit in Reynolds number or pump power calculations can lead to major design errors.

Final Answer:
both (b) & (c)