we all know current is flow of electrons in the conductor........in generation of power the emf induced in the conductor causes current once the valance electrons are removed from their respective orbits(ie the flow of current) how the electrons are retained in their atoms...if someone has any answer please tell me..

In a solid conductor all the valance electrons are in a sea of free electrons, when you are flowing current you are flowing this sea from a source to a drain, you will be pushing more electrons in as you remove them...

 

http://en.wikipedia.org/wiki/Free_electron_model