Electromagnetic Fields

Electromagnetic fields are everywhere, because, as we learned in physics, an electrical currents create electromagnetic fields. Hans Christian Oersted found this out on accident when he had a wire with current flowing through it and a table full of compasses, so I thought it would be a great idea to go around the house this weekend with a compass to observe for myself the effects of electromagnetic fields. It was cool (For real!). My compass reacted according to the strength of the electromagnetic field generated by whatever device around the house I tested because the compass is simply a magnet that points to a magnetic south pole. I tested my compass with a cell phone, a clock radio, and a 500W computer power supply unit. The compass seemed to react most to the cell phone at its base, which is where I suspect the antenna is located, and second most to the clock radio. Yay for physics observations in everyday life!

EDIT (3/11/09): Video is up now.



EDIT (3/10/09): I have to make a correction to the concept explained in this post. Upon closer examination, I noticed that my phone caused movement of the magnetic needle of the compass even while it was turned off, so the electromagnetic field could not have been the main factor for the needle's deflection. Whoops =(. Through further research, I found that it was probably the magnet in my phones speaker that caused the deflection. This is supported by the fact that the strength of the attraction/repulsion is stronger as the needle gets closer to the speaker area on my phone. Furthermore, the clock radio also has a speaker. Magnets are a component of a speaker. From my video, I can conclude that the south pole of my phone's speaker magnet faces in the same direction as the face of my phone, and north pole of the speaker magnet faces the same direction as the back of my phone.