What do leyden jars measure

I tried some similar way such as using a large capacitor in parallel but unable to get reasonable result. Another possible way is to by-pass the chain:. We did some measurement with the Leyden jar used in later experiments following the method above:.

Result: The measured result is pF by direct connection. Here the size of the jar is 21cm in height, 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.

They are also used, then as now, to demonstrate basic electric principles shocking audiences, sometimes, in more ways than one. We, too, shall demonstrate here without the shock. Use the wand position slider to approach the discharge wand to the charged Leyden jar.

As you see, one arm of the wand will draw near with the negatively-charged metal ball, the other will draw near the positively-charged lining outside the jar. Furnished this pathway, these oppositely-charged particles will, when the wand gets close enough, jump across the spark gap with a dramatic little flash and rush towards each other. Interactive Tutorials. Last modified on 17 June Here is my actual Leyden jar.

In this case I used a water bottle instead of a plastic cup as seen in the video. The multimeter gives a capacitance value of 1. Is this value even legit? What if I assume that the foil wrapped around the bottle is like a parallel plate capacitorit kind of is if you unwrap it.

In that case, I can estimate the capacitance value and compare the to the meter's value. This particular water bottle has a height of about 10 cm and a diameter of 5. That means that if I rolled out the foil, it would have an area of 0. The inside water in the bottle has approximately the same area. Now, what about the separation between plates? I'm just going to roughly estimate this with a value of 2 mm 0. I will guess that plastic has a relative permittivity of 2.

Using these values, I get a capacitance of 0. Ok, so either my bottle thickness is way off or this meter isn't giving a very accurate value or both. The energy stored in a capacitor can be found by:.

I have a value for the capacitance I am going to use the value from the multimeter. But what about the voltage? Here's where I can use a great trick. Air has an electric field breakdown value of around 3 x 10 6 Volts per meter. This is the value of the electric field in air at which it switches from an insulator to a conductor. If I can estimate the length of the spark, I can use that to get the value of the capacitor voltage. Let's say the spark was 3 mm, this would give a voltage of 9, volts.

Now I just have to plug this into the energy equation and I get a stored energy of 0. That's not much, but it is something. I'm pretty sure you can charge up a Leyden to get a much bigger spark probably over a centimeter with much higher energy.