38. All atoms have moving electric charges. Why, then, aren't all materials magnetic?

39. If you place a chunk of iron near the north pole of a magnet, attraction will occur. Why will attraction also occur if you place the same iron near the south pole of the magnet?

42. What kind of force field surrounds a stationary electric charge? What additional field surrounds it when it moves?

47. What kind of force field surrounds a stationary electric charge? What additional field surrounds it when it moves?

48. We know that in the Northern Hemisphere a compass points northward because Earth is a giant magnet. Will the northward-pointing needle point northward when the compass is brought to the Southern Hemisphere?

57. We know that in the Northern Hemisphere a compass points northward because Earth is a giant magnet. Will the northward-pointing needle point northward when the compass is brought to the Southern Hemisphere?

62. Why are northern Canada residents bombarded by more intense cosmic radiation than Mexico residents?

65. Your study partner claims that an electron always experiences a force in an electric field, but not always in a magnetic field. Do you agree? Why or why not?

68. A cyclotron is a device for accelerating charged particles to high speed as they follow an expanding spiral-like path. The charged particles are subjected to both an electric field and a magnetic field. One of these fields increases the speed of the charged particles, and the other field causes them to follow a curved path. Which field performs which function?

71. If you had two bars of ironone magnetized and one unmagnetizedand no other materials at hand, how could you determine which bar was the magnet?