Question

Based on the design the Tip Speed ratio can be less than 1 or greater than 1

Answer 1

1 is the answer to the question hope you like

Answer 2

Rotating rotor speed always depends on the Tip Speed ratio (TSR).  

To extract the maximum efficiency from the wind turbines, the TSR must be optimum as possible. This TSR varies with designs of the turbines. TSR relies on the speed of both the wind and the tip of the turbine blades to identify the turbine's speed of rotation.  

VAWT (Vertical Axis Wind Turbines) are of varying types with varying TSR ratio. One of them is Darrius Wind turbine which needs a higher TSR value (>1) (i.e., spins many times than the wind speed) for producing an aerodynamic lift to process electricity.  

In contrast to this is a Savonius Wind Turbine which needs a lesser TSR value (<1) (i.e., cannot spin more than the speed with which the wind flows) since this one is a drag type turbine and not a self-starting model.