In a certain circular region of radius 8.50 cm, the electric field is directed into the page, has a uniform magnitude, and is decreasing at a rate of 38.0 V/m · s. The electric field everywhere outside this circular region is zero. Determine the magnitude and direction (use the direction rosette for this) of the magnetic field at the location A which is at a radial distance

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.