The research aims to determine the fundamental principles and working systems of Microhydro power plants from a physical standpoint as an effort to provide and develop contextual learning resources. This study was conducted using literature, observation and interview methods. The results found that PLTMH had three main components i.e. water as energy source, turbine, and generator. The energy conversion scheme on PLTMH that uses the head is as follows: 1) The potential energy of water from the reservoir is converted into kinetic energy on the rapid pipeline, 2) water kinetic energy converted into mechanical energy by water turbine, 3) changed mechanical energy into electrical energy by generators. The water turbine based on the working principle is divided into impulse turbines and reaction turbines. The impulse turbine utilizes a change in water momentum before and after crashing the turbine's sudu, while the reaction turbine utilizes pressure differences on the surface of the Sudu. The generators work based on electromagnetic induction principles. When the rotor generator is attached to the turbine spinning, the conductor coil will cut off the magnetic field line so that the induction voltage arises.