This document discusses turbines and hydropower. It classifies turbines based on head and efficiency, and describes axial, radial, and mixed flow turbines. Specifically, it examines the Pelton wheel, Francis turbine, and Kaplan turbine, covering their working principles, the work done by water on the runner, and draft tubes. It also discusses specific speed, unit quantities, performance curves for turbines, and governing of turbines. The document provides several problems analyzing turbines and hydropower plants. It includes links to YouTube videos explaining the Francis and Kaplan turbines and comparing different turbine types.