Electric Meter

Work It, Jesse!

I know that this journal entry is a week late, but I hope these videos will make up for it. Here we have Jesse making himself happy...by creating current and light! The big coils of conductive wire were attached to an ampmeter, and when Jesse moved the coils in and out of the horseshoe magnet a current was created that we could see on the ampmeter, and also in the bulb that apparently lit up for a brief moment. The change in the magnetic field inside the coil as it moved in and out of the space between the poles of the horseshoe magnet induced an emf that caused a current. This phenomenon is called "motional electromagnetic induction: Moving a wire through a magnetic field induces an emf." Current flows because "the motion of the wire causes the electrons in it to be moving in a magnetic field, and the magnetic field exerts a force on the moving electrons that is directed along the wire." The faster Jesse moved the coil in and out of the magnet, the more current he produced. Alex couldn't do it because he didn't have as much energy as Jesse did. Jesse was apparently able to create enough current to make the tiny bulb light up, but I was recording so I didn't get to see it :( . There are four factors which affect the emf:

"1. The strength of the magnetic field. The stronger the field, the greater the change in field strength as the loops move by, and the greater the induced emf.

2. The speed of the wire relative to the magnetic field. The faster one passes by the other, the greater the emf.

3. The area of the loops. The greater the area enclosed by each loop, the greater the emf.

4. The number of loops of wire. Increasing the number of loops increases the total area through which the field passes. This, too, increases the induced emf."

I hope you found the videos entertaining and the entry informative! =)

Sorry it's so late, Mr. Kohara. :)))