exam paper vs question sheet

exam paper and question sheet both are nouns.

Word	Noun	Adjective	Verb	Adverb
exam paper	Yes	No	No	No
question sheet	Yes	No	No	No

As nouns, exam paper and question sheet are synonyms defined as:

Other synonyms of exam paper include examination paper, test paper.

exam paper (noun)	question sheet (noun)
a written examination	a written examination