I ask no questions but receive a lot of answers. What am I?

Question

There are (n+1) people in a party, they might or might not know each others names.

There is one celebrity in the group(total n +1 people), celebrity does not know any of n peoples by name and all n people know celebrity by name.

You are given the list of people's names(n+1), You can ask only one question from the people. DO YOU KNOW THIS NAME ?

HOW MANY MINIMUM NUMBER OF QUESTIONS YOU NEED TO ASK TO KNOW THE CELEBRITY NAME?

NOTE: assume all names are unique.

Answer 1

phone or door bell

Answer 2

answering machine