Yamaka isn't the correct word? I could swear that's what I've always heard.
Depends a little om one’s family or community.
I grew up in Minnesota and rarely heard it pronounced any way besides “YA-muk-kah.” These days most people just use the Hebrew kippah (KEE-pah).
Yiddish has a lot of variations in pronunciation.
Like a lot of things in Jewish life, it depends on who your zayde (grandfather) is.
Different languages - “kippah” is Hebrew, “yarmulke” is Yiddish.
Since most Jews in the USA have European ancestors you commonly hear the latter. As the last of the Yiddish speakers pass on, “kippah” has come into more common use.