のみ・ばかり: the difference
のみN2
Meaning
Only
Past papers
Example
あとは結果を待つのみだ。
Now, we only have to wait for the results.
ばかりN3
Meaning
Just, Only, Nothing but
Past papers
Tested 5 times in past papers
Example
最近はお菓子ばかり食べているから、お腹がでてきた。
Recently, I've been eating nothing but sweets, so my stomach is bulging out.
How to tell them apart
「のみ」: dignified written style; a plain limit with no negative feeling.
「だけ」: neutral; both speech and writing.
「ばかり」: strong feeling, as in 'doing nothing but...' (with blame) or 'nothing but...everywhere'.