Which of the following describes the flow characteristic when the viscosity of the fluid increases?

When the viscosity of a fluid increases, the flow characteristic is associated with decreased laminar flow. Laminar flow occurs when a fluid flows in parallel layers with minimal disruption between them. This type of flow is typically smooth and orderly, and it is influenced by the properties of the fluid, including viscosity.

As viscosity increases, the internal friction within the fluid increases, making it more resistant to flow. This results in a situation where the fluid's ability to maintain an orderly flow is compromised, leading to a decrease in the extent of laminar flow. Higher viscosity fluids tend to experience more friction, which disrupts the layers of flow and can lead to the transition to a more chaotic flow pattern. However, with high viscosity, the condition favors laminar flow less, thereby decreasing its prevalence.

In practical terms, if viscosity increases significantly, the flow might become more turbulent, but it predominantly reflects a decrease in laminar flow under typical scenarios. Thus, the correct choice highlights the fundamental relationship between fluid viscosity and flow patterns.