A compass is moved from the Northern Hemisphere to the Southern Hemisphere. Assume that the only magnetic field that acts on the compass is the Earth's magnetic field, and that this field is the same as the field of a dipole with the locations of the poles described in the textbook. When the compass is moved through the equator, the magnetic needle of the compass will change direction relative to the meridian ________.
1) by 90 degrees.
2) hardly at all.
3) by 180 degrees.
4) randomly and rapidly