Torque experienced by compass needle

AI Thread Summary
The torque on a compass needle is calculated as the product of its magnetic moment (m) and the Earth's magnetic field (B). The compass needle aligns with the magnetic field, but torque occurs due to the angle between the needle's magnetic moment and the magnetic field direction, which can vary based on location. The angle of dip, or inclination, affects the components of the Earth's magnetic field, contributing to the torque experienced by the needle. As the compass needle seeks equilibrium, it rotates until it aligns with the magnetic field. Understanding these dynamics is crucial for comprehending compass behavior in different geographical locations.
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The torque experienced by the compass needle is m X B , m being the magnetic moment of the compass/magnet and B being the Earth's magnetic field. The magnetic moment is along the axis pointing from South to North and the magnetic field will depend on where the compass is on the surface of the earth.

I can't understand how it's experiencing a torque. Doesn't the needle always point in the direction of the field? Won't the axis be in the direction of the field itself? How is the angle between them anything other than 0°?
How does the angle of dip contribute to this torque? Infact, I can't even understand which component of the Earth's magnetic field is causing this.
Any links to images of the field etc. would really help.
 
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the Earth's B field will torque it until it reaches equilibrium.
 

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