Pronunciation of EX-

ex- is pronounced as /ɪks/ when it is UNSTRESSED	ex- is pronounced as /ɛks/ when it is STRESSED or SEMI-STRESSED
extreme, extract (v), expect, export (v), exterminate, excite, expand, extend, experience	expert, extra, extract (n), export (n), excellent, exploration, exploitation

Ex- as a prefix meaning ‘former’ is pronounced as /ɛks/: ex-girlfriend, ex-teacher, ex-husband

Ex- is sometimes pronounced as /ɪɡz/:exact, exist, exhaustion