1. The problem statement, all variables and given/known data This is more like a concept question. If you have a solenoid with AC frequency f, placed in close proximity on top of a wire with both ends fixed, and projected parallel to it, why is the frequency of the standing wave observed in the wire equal to 2f? 3. The attempt at a solution This is about magnetic forces and fields which I haven't studied yet. This is out of curiosity, after seeing that statement without any explanation in my last lab. Thank you if you can clear this for me.