In classical mechanics, it's pretty straight forward for me to apply it(sometimes...), and really intuitive to picture it. However, when I kick it up a notch... to apply Newton's 3rd law in electrodynamics, my brain malfunctions... Simplest example I can think of, a conductor carrying a wire placed inside a magnetic field like so: This diagram shows it all, when current flows in the conductor perpendicular to the magnetic field of the magnet, there is a Lorentz force created. What is the action? The Lorentz force? What is the reaction then... a magnetic force acting on the magnet ? Another example, instead of using a permanent magnet which has a complexity of it's own(with magnetic moment) lets use two wires like so: This example I think is easier for me to apply Newton's 3rd law, due to the current flow of each wire and their magnetic fields they both have equal and opposing forces acting on one another? I mean, if the blue wire attracts the green wire, likewise the green wire will attract the blue wire and vice versa in the case of repulsion due to the opposite current flows. So, the Lorentz force is the action and reaction force in such systems? I've read other thread related to this topic, some members related momentum to this, and how it will be conserved can someone please explain that point too?