Viscosity is the ...

• A. Thermal property
• B. Internal resistance
• C. Color of the liquid
• D. Temperature

Answer: (B)

Viscosity is the internal resistance to flow inside a liquid. It describes how strongly the molecules resist sliding past each other due to cohesive forces and the fluid’s structure. A high-viscosity liquid, like syrup, flows slowly because its molecules cling together and oppose deformation, while a low-viscosity liquid, like water, flows easily. It’s not a thermal property, nor the color of the liquid, and although temperature affects viscosity (raising temperature usually lowers it), viscosity itself is this internal resistance to flow.