5/14 Faraday's Law and Magnetic Force

Professor Mason uses a Halls Effect sensor to find the magnetic field inside the classroom. When he spun around the classroom for the 10 seconds Logger Pro took data for, it showed a sinusoidal behavior. This is because when mason spins basically spinning a compass around and the needle's behavior is what we observe on the graph. 

We made a copper coil and used the same sensor used to measure the magnetic field of a coil of 1 loop of wire up to 5 loops of wire. Our measured magnetic field is shown as this graph

We drew a current going down 2 wires that are in parallel and were asked to find the force vector created by their magnetic fields. We found that with the right hand rule, the force cancels in the middle and goes in through the board on the left and out through the board on the right.

 

In these two pictures, Professor Mason uses an ancient device to measure the magnetic field when moving a metal rod at inside a coil of wires. We observed that when there was no movement, there was no magnetic field. 

In the above 4 pictures, we created a magnetic field that would induce a magnetic field on the object we placed around it. We tried this with 3 different types of material, wood, copper, metal. We observed that with a wooden ring, nothing would happen. The wood is not a conductor therefore there is no way for the current to travel through it. We then tried copper, a very poor conductor. We found that the copper ring jumped a bit but because it does not conduct the current well, it only did a small jump. We then tried 2 different metal rings, one thin and one thick. The thick one jumped up a bit and stayed floating. The thin one flew off the tube. Because metal is such a good conductor, it was able to conduct a high enough current to create a magnetic force in the downward direction. The thin metal ring flew off because it was just as good of a conductor but was lighter so the magnetic force larger.

We calculated the flux of 2 plates oriented differently. The flux from the magnetic field when plate is parallel to the magnetic field is 0 and the magnetic field when the plate is perpendicular to the magnetic field is the magnetic field times area. The actual formula is the dot product of the magnetic field and the area. We were then asked what elements could change the magnetic field. From our experiments, we answered the 4 in orange. 

We have 2 tubes, one aluminum tube and one acrylic tube. This experiment was to see what would happen if a magnetic object was dropped through the acrylic tube and the aluminum tube.

This is our results from the previous experiment. We found that when the magnetic object was dropped through the aluminum tube, it went through significantly slower than it did through the acrylic tube. Even though aluminum is a poor conductor, it still managed to create a large enough magnetic force from the magnetic object's velocity to slow it down significantly. We then derived its relationship.  

The top graph shows a magnetic field graph vs. time and the bottom graph shows an emf graph over time. We found them to be sinusoidal. If we were to interpose the graphs, we would get the x-axis.