The Leyden jar was originally used to store electric charge after some rubbed object is charged like your socks in the dryer. There were two common variations of the Leyden jar, let me illustrate both. For version 1, there are two pieces of metal around a glass cup.
One piece of metal sits inside the cup and one is on the outside. However, for version 2 the inside metal is replaced with water. Yes, you can replace the metal with water as long as the water is an electrical conductor. Most water conducts electricity, but you could add a little salt just to make sure. But how does it work? Really, the Leyden jar is just a capacitorthat's all. The simplest capacitor contains two parallel metal plates with nothing in between them. If you add charge to one side of the plates, this will pull the opposite charge onto the other plate assuming there is a path for the charge to get on there.
This is what it would look like. The ratio of charge on just one plate to the potential difference is defined as the capacitance such that. The units for capacitance is the Farad.
However, it turns out that the value of the capacitance only depends on the physical configuration of the device. In this case that means the size of the plates, their seperation distance and the material that is in between them. For a parallel plate capacitor like above the capacitance can be calculated as:. The area of the capacitor is A and d is the distance between plates. Even though the Leyden jar is in a different configuration, it basically works the same way.
The outside metal can be grounded simply by holding it with your hand or running a wire to a metal water pipe. When you bring an charged object like a plastic pen that your rub in your hair near the metal in the middle, this will add charge to the water and draw the opposite charge to the outside metal. It's possible to get this up to fairly high voltage since the glass in between the water and metal acts as an insulator.
I guess you can figure this out by how it worksbut still, let me show you how to make one. Here is a video I made to go along with this episode of MacGyver that walks you through this build. View Iframe URL. Improve this question. Austin Gae Austin Gae 2 2 silver badges 11 11 bronze badges.
Add a comment. Active Oldest Votes. For a parallel plate capacitor like above the capacitance can be calculated as: The area of the capacitor is A and d is the distance between plates. Coming back to your question, When a charged object is placed on the metal conductor sticking outside of the jar, the electricity flows from the nail to the foil inside, while the foil outside is properly insulated from the nail. Improve this answer. Shishir Maharana Shishir Maharana 3 3 silver badges 12 12 bronze badges.
Like an example? It can be charged by any means. You can charge it by conduction or induction. That is actually not the central point of argument.
The outside foil needs a charge to pull the opposite charge to the inside foil. And also, the foil coatings stop short of the mouth of the jar, to prevent the charge from arcing between the foils. Basically, there is a positive charge on the outside and a negative charge on the inside.
You may also want to do this: nationalmaglab. AfiJaabb AfiJaabb 2 2 silver badges 10 10 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. Click the blue charge button to start this tutorial, and observe as the electrons in the current depicted as little yellow particles travel through the wire to the brass rod.
As you can see, these electrons are conducted down the metal rod, down the chain, and to the inner lining of the jar to which the chain is attached. But there they hit a roadblock, for their way is barred by the glass, acting as an insulator also called a dielectric , and they accumulate in the internal metal lining.
Meanwhile, on the other side of the glass, electrons in the outer metal lining are repulsed by the accumulating electrons on the internal lining. The repulsed electrons leave behind a net positive charge depicted by red plus signs on the conductor.
So you wind up with two metal plates of equal but opposite charges. Another interesting thing going on here but not depicted in the tutorial is that the molecules in the glass jar respond to the charges, too; the negative charges in the molecules shift toward the outside, positively-charged metal, and the positive charges orient themselves toward the negative charges on the inside.
This is called polarization. Now what do you do with the electricity once you trap it in the jar? Well, people used to use collections of Leyden jars like batteries, to power any number of things.
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