In: Physics
If you were conducting the wire and compass experiment (Part A) near the equator instead of Oregon, would it be necessary to use more or less wire current to cause the compass needle to deflect? Hint: Consider both components of Bnet. Explain your reasoning.
Magnetic compasses work fine at the equator.
Actually, they work best there. A magnetic compass has a north and south pole as does the earth. the compass magnet tries to align with the magnetic field of the earth with it's polarity reversed. All magnets do this.
Your confusion might come from the magnetic north and true north/south not being the same. The Earth's magnetic field is not uniform and also not at true north/south (Earth's spinning axis).
Some compasses are made to correct for local differences, assuming you will use them in the area of the world they are corrected for.
Dip becomes a problem in compasses as you get closer to the poles. Dip is the result of the magnetic field of the earth not being level. This causes the compass needle to want to dip down to the north when in the northern hemisphere. When is the southern hemisphere, the reverse is true. Spherical compasses are not affected by this.
But the main reason for spherical compasses is that they are self-leveling.