Solution:

• The Kaplan turbine is a propeller-type axial flow reaction water turbine which has adjustable blades.
• It was developed in 1913 by Austrian professor Viktor Kaplan, who combined automatically adjusted propeller blades with automatically adjusted wicket gates to achieve efficiency over a wide range of flow and water level.
• Since it is a reaction turbine, so the reaction force of leaving water is used to turn the runner of the Kaplan turbine, As the water flows through the twisted blades a lift force is generated in the opposite direction of the leaving water and that lift force causes the blades to rotate.