One example could be: "His argument was plausible, but in the end it turned out to be false." Generally plausible means that something is reasonable or likely to be true, but we tend to use it negatively (ie, it looks true but isn't really.)
How To Put Plausible In A Sentence?
He presents as a very plausible young man
That is a plausible explanation but would you please elaborate a bit more on the subject?