Teacher:In this task, you are given a paragraph, and your task is to construct a question from the given passage. Construct question in such a way that (i) it is well explained in the paragraph, (ii) the words may/may not be present in the paragraph, (iii) it should start with what/how/describe. Avoid creating a question that (i) is just relevant to one or two sentences, and (ii) not relevant to passage. 
Teacher: Now, understand the problem? Solve this instance: A reservoir is formed. The collects water converting the water's from kinectic to potential. The water is forced through a turbine under the reservoir. The turbine spins and so does the generator connected to it. The water's energy is turned into electrical energy. The transformer converts electrical energy from the generator to a high voltage. The national grid uses high voltages to transmit electricity through the power lines. 
Student:
How is hydroelectric electricity generated?