You can write a tricky formula on it.
You can write an answer that you know you can't mug up.
You can even write a full chapter.

But you have to be super cautious.
Teachers, professors all will be watching you.
And, if you get caught, nobody will be able to stop you from getting debarred.
And, most importantly Anna may not like you at all.

Simply put, Chothas are those small pieces of paper what you use as external memories in exam hall. Boring people may call the whole act cheating.
But, you know how fun it is. Right?

But when it's used behind a statement, it has an interesting connotation. It then becomes a more masculine and abrasive expression of na. Then it shows some amount of anger, frustration and all that...

Ghosa Ghosa means study in engineering colleges!