Ethnic Experiment

Scenario 1: A first century Jew* meets another Jew in Judaea. What term would they use to identify their ethnic background?
Scenario 2: A first century Jew meets another Jew in Galilee. What term would they use to identify their ethnic background?
Scenario 3: A first century Jew meets another Jew in Ephesus. What term would they use to identify their ethnic background?
Scenario 4: A first century Jew meets a Samaritan. What term would the Jew use to identify his ethnic background?
Scenario 5: A first century Jew meets a Syrian. What term would the Jew use to identify his ethnic background?

*For discussion of the complexities involved in the term "Jew" and its relationship to Israel on the one hand, and on the other hand, to the ancient Greek, Latin, Hebrew and Aramaic terms, Ἰουδαῖος (Ioudaios), Iudaeus, יהודי (Yehudi) and יהודאי (Yehudai), see my What's in a Name? series from way back in 2007.