$F$ is a field. I consider that if Quotient ring of $F $by $N$ exists, then it would be zero ring or isomorphic to $F$.
$F$ is field, so it is ring. Suppose that $N$ is an ideal of ring$F$. And consider Quotient ring of $F$ by $N$.
If $N$ is zero set, then $F/N$ is equal to $F$ Otherwise N contains nonzero elements. And a Quotient Ring <$F/N$,+,•> can be a field.
That is my ideal. Please give me idea How to think more here.