# Why reversing the direction of electric current reverses the magnetic fields' direction?

I don't understand why magnetic field gets reversed when the electric current is reversed. So I searched on the internet but couldn't find any answer. Could someone plz explain this phenomenon?(with reference to the the following article on quora if possible:Answer to Why don't stationary charges produce magnetic fields like moving charges? by Ashwin https://www.quora.com/Why-dont-stationary-charges-produce-magnetic-fields-like-moving-charges/answer/Ashwin-815?ch=15&oid=109456771&share=00a43b46&srid=ughGY2&target_type=answer)?
I don't know relativity,Lorentz invariance,etc, I have just started to learn electromagnetism. So please explain in as much layman's term as possible.

• Dec 30, 2021 at 13:32
• Dec 30, 2021 at 13:32

I you have a vector $$v$$ then $$-v$$ is the vector in the opposite direction. If you look at Biot Savarts law: https://en.wikipedia.org/wiki/Biot%E2%80%93Savart_law and you reverse the current it means that you have to flip $$l$$ to $$-l$$ and that flips $$B$$ to $$-B$$.