「所定」と「固定」の違いは何でしょうか？ Google translate gave be result below > = Predetermined > > = Fixed Which word is used when?

* is a no-adjective. is a transitive suru-verb and no-adjective.

> : OK
> : OK
> : OK
> : NG

* Obviously, fixation of a tangible object is but not .

>
> The picture is fixed to the wall.

* means "it's been already determined/established by someone", means "it won't change". A may be revised in the future, whereas a is, um, fixed.