What are the differences between subject and subjected?

very subtle difference

examples:

http://www.learnersdictionary.com/qa/subject-to-and-subjected-to

tense

Subject is a topic, like "My least favorite subject in school is either math or science." Subjected means you have to do something often to pay a price for something bad. For instance, "Cory Wilks is subjected to two years in jail for robbing a house."