A small compass is held horizontally, the center of its needle adistance of 0.120 m directly north of a long wire that isperpendicular to the earth's surface. When there is no current inthe wire, the compass needle points due north, which is thedirection of the horizontal component of the earth's magnetic fieldat that location. This component is parallel to the earth'ssurface. When the current in the wire is 12.0 A, the needle points15.0° east of north.
(a) What direction does the current inthe wire flow, 1 - toward or 2 - away from the earth's surface? Give the number of the correct answer.
(b) What is the magnitude of the horizontal component of the earth's magnetic field at the location of the compass?