Behavior of compasses AFTER the magnetic pole

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  • Thread starter jaumzaum
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Main Question or Discussion Point

So I know that a compass points to the south magnetic pole, that is near the north geographic pole. Let's consider the Earth to be a magnetized bar with all 4 poles aligned (for didactic purposes). The compass will try to "follow" the south magnetic pole, so, if I am in the Equator for example, it will point towards the geographic North. What if I pass the magnetic south pole (I am below the geographic north and above the magnetic south pole)? In my understanding the compass will continue to points towards the south magnetic pole, but in that case it will be pointing towards the opposite way, the geographic south!

Is this statement correct?
 

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  • #2
BvU
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No. The way you set up your senario means the needle will rotate 180 degrees when you step over the south pole.

Provided it's a very sensitive compass: the magnetic field there points skywards !

Wiki pic:

compare lower left needle with lower right

1589497693236.png
 
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No. The way you set up your senario means the needle will rotate 180 degrees when you step over the south pole.

Provided it's a very sensitive compass: the magnetic field there points skywards !

Wiki pic:

compare lower left needle with lower right

View attachment 262789
Thank you @BvU. Exactly in the magnetic south I am sure it will, but what about a little to the right of it, e.g. in the middle ground of the south-magnetic and north-geographic? I would say the field would have a much higher radial component, but the tangential component there will not be zero, and will make the compass point towards the geographic south, am I right?
 
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BvU
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e.g. in the middle ground of the south-magnetic and north-geographic
I thought that's not in your scenario

magnetized bar with all 4 poles aligned
Did I misinterpret this ? 2 magnetic and 2 geographic is all I could think of.

e.g. in the middle ground of the south-magnetic and north-geographic
...
the compass point towards the geographic south, am I right
Yes. The compass points to the magnetic pole. It does not know about the geographic pole.
 

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