Which episode was Ranma's curse revealed?

Answer 1

Episode 156 "Bring It On! Love as a Cheerleader - Part 2."

This is were the students from Furinkan High show that they first realize that Ranma and girl Ranma are the same person, thanks being to Ranma's dad for that. Though, in the Manga, the curse is revealed when Ranma is fighting Ryoga when he first comes into the series, during a battle the water sprays Ranma, his shirt is ripped and Ryoga doesn't recognize Ranma in his girl form. This way though makes more sense and is more flowing than Hiroshi and Daisuke stating in the crowd with confusion that why is girl Ranma being addressed as "Ranma" during the Cheerleading match.

When Ranma fights Kodachi Kuno for the first time in the Gymnastic battle, girl Ranma uses his real name, so you'd think they'd ask when the announcer announced his name... but I think this is due to the fact that the Manga is more organized in story line than the Anime lol.