[Alpha-Omega]

I understand the part about Hans Oersted's observation.

When electric current passes through the wire, the wire would have a magnetic field around it. This magnetic field would interact with the magnetic field of the compass needle, which makes it move.

However, I'm a bit confused on Andre Ampere's observation.

I know that they are within each's magnetic field and that the magnetic field lines between the wire cancel out, but I don't see how that results to a force which causes them to move towards each other.

How do these wires end up attracting each other? (Maybe a diagram with your answer would help to explain it)

[Antimony]

If you imagine the field produced by wire two intersecting wire 1, it would intersect it at 90deg coming out of the page (thumb points in direction of current and fingers show field lines). So you can now use flem's left hand rule on wire 1 with the first finger pointing out of the paper(direction of the field of I2), the second finger pointing along I1 and the thumb (force) points towards wire 2. The same can be done to wire 2 by imagining the field lines produced by wire 1 intersecting it.

You can also imagine a wire feeling a force towards the point where the field lines cancel out

[Alpha-Omega]

(Original post by Antimony)
If you imagine the field produced by wire two intersecting wire 1, it would intersect it at 90deg coming out of the page (thumb points in direction of current and fingers show field lines). So you can now use flem's left hand rule on wire 1 with the first finger pointing out of the paper(direction of the field of I2), the second finger pointing along I1 and the thumb (force) points towards wire 2. The same can be done to wire 2 by imagining the field lines produced by wire 1 intersecting it.

You can also imagine a wire feeling a force towards the point where the field lines cancel out

I was thinking of something else that's why I didn't understand it. Thanks for the answer.