i watched a movie about a teacher who kidnapped his whole class and took them to his place.he drugged them and when they woke up they were naked and in animal cages with electricity and all. if they were good he rewarded them if not he woulkd turn on the juice.he did not kill them he let them excape in the end after he faked his own death and taught them a lesson.i dont know what movie this is but its before 2005
Probably Learning Curve (1998)
I agree that it was Learning Curve (http://www.imdb.com/title/tt0134613/).