Question

will you please explain AC generator

Answer 1

Ac generator is used for generating ac current.
By the help of moving magnet.

Answer 2

AC GENERATOR.
  A.C. generators or alternators (as they are usually called) operate on the same fundamental principles of electromagnetic induction as D.C. generators.

    Alternating voltage may be generated by rotating a coil in the magnetic field or by rotating a magnetic field within a stationary coil. The value of the voltage generated depends on-

                   ~  the number of turns in the coil.

                     ~strength of the field.

                      ~ the speed at which the coil or magnetic field rotates.