In large generators in power plants, rotate inside a coil of wire to produce an electric current

Answer;

Magnets

In large generators in power plants, magnets rotate inside a coil of wire to produce an electric current.

Explanation;Generators are devices that use electromagnetic induction to convert mechanical energy to electrical energy. In power plants, large wheel known as turbine that rotates when pushed by steam,wind, or water and provides mechanical energy to a generator.Generators are used in power plants and have very large quantities of copper wire spinning around inside very large magnets, at very high speeds. A turbine spins the shaft that runs the generator. Eventually, electric current is generated.