Which questions are asked in interview for a data entry operator?

That depends in which firm you are applying for,,, therefore make your question a bit clear...

However, in general the question for Data Entry Job shall be as follows :
1) Regarding computer knowledge about MS office packages.
2) Your Typing speed.
3) English languauge ablity.
4) Exp. about using office equipments.
5) Expected Salary ( lol)

Hope these gave you a brief idea about your interview... Good Luck