21. Magnetism is produced by the motion of electrons as they
a. move around the nucleus.
b. spin on their axes.
c. both A and B
d. none of the above
22. If you put a small compass in a magnetic field, the compass will
a. line up in a direction parallel to the magnetic field lines.
b. swing randomly.
c. line up in a direction perpendicular to the magnetic field lines.
d. seek electrical charge concentrations.
23. Magnetic field strength is
a. strongest close to a magnet.
b. constant everywhere around a magnet.
c. strongest far from a magnet.
24. Magnetic domains are
a. regions that may or may not be magnetized.
b. clusters of atoms randomly aligned.
c. regions of atoms magnetically aligned.
d. blocks of material.
25. Earth's magnetic field is most likely due to
a. millions of small magnets buried in Earth.
b. a magnetized solid inner core of Earth.
c. convection currents in the molten part of Earth's interior.
d. the rotation of Earth acting on all of Earth's electrons.
