Can anyone explain this in futher detail?
Answer
Hello Lauren,
I think your choice should be influenced by the interest you had in the various topics that you studied. By now you have been exposed to several different topics. It's true that not all topics easily adapt to a project. When I was in your shoes, I chose a project in the electrical field. And it turned out that my career was in Electrical/Electronic Engineering.
What I built was a demonstration of the principle that a current flowing at right angles to a magnetic field experiences a force at right angles to both the direction of the current and the magnetic field. I had technical problems and I have since considered several better ways I could have done it. My best idea is that I could have had the current flow in a path like the ropes and seat of a playground swing. The seat of the swing could have been the portion of the circuit where the current flowed perpendicular to a vertical magnetic field. By turning the current on and off at the right times, the swing could have developed quite a significant swing.
The immediate application of this phenomenon would be motors. I did not work specifically on motor design. But considering that I started out to become a working physicist, to end up designing electronic circuits shows a relation to that high school project.
So my advice is to consider which topics have interested you more than others — your choice may just point you towards your eventual career.
I hope this helps,
Steve
I got this idea from a firend of mine and well, I don't want to breck it to him that I have no idea what he is talking about. Can anyone futher explain what he is talking about in easier to understand language than what he used??
Tagged with: demonstration • electrical field • Electronic Circuits • electronic engineering • eventual career • firend • phenomenon • physicist • playground swing • principle • right angles • ropes • shoes • vertical magnetic field
Filed under: Electronic Circuit Projects
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He was explaining how to demonstrate a property of DC electrical currents flowing in the presence of a steady magnetic field. The electric current creates its own magnetic field, and when the current is at right angles to an external magnetic field, like from a horseshoe shaped magnet, then a force at right angles to both the electric current and the external magnetic field will be applied to the wire carrying the current.
So, imagine a bar magnet whose ends are bent into a horseshoe-shape, and the ends (the magnetic poles) positioned vertically, one above the other. The magnet is held, on the curved end opposite its two poles, with a bench vice so the magnet won’t move.
Now imagine a long pair of thin wires hanging down above the magnet, with one wire on one side and the other wire on the other side of the magnet. The two wires extend down to half-way between the magnet poles and then a third, horizontal, wire is connected between them so that this third wire goes between the magnetic poles.
If you now connect a dry-cell between the two hanging wires, an electrical current will flow from the positive side of the cell, down one of the wires, across the horizontal wire, and back up the other wire to the negative side of the cell. This current will cause a magnetic field to encircle the wires. In the horizontal wire, located between the poles of the horseshoe magnet, the magnetic field from current in the wire will interact with the magnetic field between the horseshoe magnet poles to create a force that will deflect the horizontal wire sideward.
There are some tricky details in getting this demonstration to actually work. First you will need a strong horseshoe-shaped magnet. Next you will need a few feet of thin copper wire, such as #36 American Wire Gauge magnet wire. For the horizontal wire, a short length (about an inch should be fine) of #10 to #14 solid copper wire should be okay. You want this to have some weight so the supporting wires will hang straight down. The hanging wires should be long, thin, and free to move, like a playground swing. Since they have to be attached to the dry-cell somehow, and you can’t leave them attached permanently or the dry-cell will quickly discharge down to nothing, a pushbutton switch will also be needed.
Gather all this stuff and together and grab a friend who is good with a soldering iron. You will need to use very fine sand paper to remove the enamel insulation off the ends of the magnet wire and make solder connections to the horizontal wire, the dry-cell, and the pushbutton switch.
If the wires are thin enough and long enough, their flexibility may provide enough of a pivot to allow you to just “tie them off” to a wooden horizontal support rod you can hold in your hand (think sawed-off broom handle). Duct tape a push-button switch and a D-size dry-cell to the wooden rod, so you can complete the circuit from the dry-cell through the two wires.
For a demonstration, maneuver the horizontal wire between the pole pieces of the magnet, momentarily press the pushbutton switch to “on” and watch what happens. The “seat” of the swing should deflect to one side, either toward or away from the “mouth” of the magnet. Carefully note the direction of deflection, the direction of the current in the wire, and the orientation of the north and south poles of the magnet. Try reversing the magnet in the vice so if the “north” pole was “up” it is now “down” (and of course just the opposite for the “south” pole) and repeat the experiment. Try reversing the direction of the current in the horizontal wire by rotating the support rod and the attached vertically hanging wires through 180 degrees. In other words, point the support rod in the opposite direction and repeat the experiment. Try to explain what is going on.