question sheet vs exam paper

question sheet and exam paper both are nouns.

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

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

Other synonyms of question sheet include examination paper, test paper.

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