Well, those "powers" are branches of the government in America. Each branch has the power to perform checks and balances on the other branches. The judicial branch has the power to declare laws made...
Real power is power that is used to do work. This is the power a light bulb uses to glow. Reactive power is power that is stored in one part of the AC voltage wave, and released in another. This...
The controlled nuclear reaction generates large amounts of heat. That heat boils water, which creates steam. The steam turns turbine blades, and the turbine generates electricity.