ANS:C - is effective over wide range of viscosities.

A turbine impeller typically produces only radial current. Here's an explanation of each option:

• Produces only radial current: Turbine impellers are designed to impart radial flow to the fluid. This means the fluid moves primarily in a direction perpendicular to the axis of rotation of the impeller blades. Radial flow is efficient for mixing and pumping applications where the fluid needs to be moved outward from the center of rotation.
• Produces only tangential current: This statement is not accurate for turbine impellers. Tangential flow is typically associated with impellers like propellers or some types of axial flow impellers, where the fluid moves parallel to the axis of rotation.
• Is effective over wide range of viscosities: Turbine impellers can be effective over a wide range of viscosities, but this depends on the specific design and application. They are generally more effective in lower to moderate viscosity fluids where radial flow is beneficial for mixing and pumping.
• Does not produce tangential current: Turbine impellers do not primarily produce tangential flow. Their design is focused on generating radial flow to achieve mixing and pumping efficiency.