Chapter 24.1 #10-15

10. A magnetic field is definately present in nature because just use a magnet and you can see that they are vector quanities and exist.

11. Some magnetic forces around us are of course in magnets, by using a compass needle and magnet to see the affect it has on the compass to see the field. Also using bar magnets getting opposite poles facing each other will show the impact of magnetic fields.

12. If the currents are in the same direction, they will repel each other but if they are facing in opposite directions, the will attract because as the saying goes "opposites attract" and that is true in this case when dealing with magnets.

13. The magnetic field around a straight, current-carrying wire is numerous circular concentric circles around the wire.

14. The observable differences that will result are that the iron fillings will move opposite their original positions because they rely on the polarity of the poles of magnets and if those change, so do they.

15. a) The rod could behave this way because the poles are being moved and so the rods are probably just now attracting each other because of the switch because opposites poles attract and like ones repel.
b) The type of replacement rod that is used is a neutral rod.