ELECTROMAGNETS

I actually was on school tours for the second lab, but I stayed after school, thanks to MM and Bert, and was able to make up the lab. (The other lab I missed for another school tout, I will make up over break because I can do it at home.) This was a hard lab to do without a partner because it involved holding things uprights on a dot as well as pushing the stop and start button to graph the magnetic field. What I had was a "magnetic field sensor", a computer interface, and the program logger pro to graph the magnetic field range.

First, I held the point of the nail to the top of the magnetic field sensor and graphed the magnetic field strength. Once I had this number established, I added coils of wire wrapped around the nail, with the other ends touching the positive/negative ends of the D battery. The magnetic field, theoretically will go up as you wrap more coils around the nail, and mine did, but it didn't jump as much as Bert or I expected.

Making and electromagnet is basically taking electricity (a battery) and a potential magnet (the nail). I ran electricity through the nail, causing it to become more magnetic. After I had done about 8 tests, the nail was magnetic enough for it to pick up a paper clip, although it didn't stay like that for a long time. And I think that the more winds around the nail you have, the larger the magnetic field because the coil generates a magnetic field when electricity is running through it.

Here is my data of the magnetic Field Strength per Number of winds:

Number of Winds Magnetic Field Strength
0 0.021
3 0.029
6 0.029
9 0.03
12 0.032
15 0.097
18* -1.104
21* -1.6

* This was when I changed the wires around and put the opposite ones on opposite sides of the batter, + or -.





I only got to Experiment 1, but over break, I will use this knowledge to build a speaker from the website Bert gave to us:

http://www.josepino.com/circuits/index.php?howto-speaker.jpc