Some people downvote questions that look simple or obvious to them, on the grounds that the OP did insufficient prior research, which is a valid downvote reason on all Stack Exchange sites. However, what's obvious to someone with some training in the relevant field may not be obvious to one without that training.
So someone may have decided your question was too trivial or obvious, and downvoted it without thinking too deeply about the thought processes that led you to ask the question. That's unfortunate, but there's not a lot we can do to prevent that.
Anyone who's played with magnets, or looked at a magnetic compass, knows that magnets and magnetic fields can twist things around. So to my mind, your question is not unreasonable or silly. But how on earth would you do research for that question? It wouldn't be easy, unless you were already rather knowledgeable about magnets. And even then, trying to find a decent answer on the internet that's understandable by a lay person may not be easy.
So I think your question is fine.
If you get 1 isolated downvote, it's generally not worth worrying about. If you get a few, and comments giving you constructive criticism regarding your question (or answer), then you probably should consider that you're in the wrong. ;)
(Note that the people giving downvotes are not necessarily the same people who give negative comments. In fact, there is a tendency to not comment when giving downvotes, to preserve anonymity, and to ward off revenge downvotes).