Solr search query case sensitiveness

I am trying to use a Solr search for some records having FirstName as;

abcd
Abcd
abcD
ABcd
abCd
abCD

Now I am trying to do a search with wildcard character support. I need to understand how exactly does the search work in terms of being case sensitive.

e.g. If I pass the FirstName parameter as ab* Vs Ab*, which records would be returned ?

Is there some way to make/force the search to be case-sensitive OR case-insensitive ?