First prepare the foils for the Inner and Outer cylinder (which will act as parallel sheets of the capacitor). Draw two rectangles of width 35mm & Length equals to the circumference of the inner and outer cylinders, then cut them out. As the aluminum sheet being only 20 Micron, it will be quite fragile so we will add a layer of paper to support it.
Make a capacitor using very inexpensive materials. Step 2: Cut two squares from the aluminum foil strip. Trim the wax paper so it is about 1/4 to 1/2 inch wider than the aluminum foil on the top and bottom. Cut the strip of wax paper so it is a little more than 4 times the width of one of the aluminum foil squares.
To make a variable capacitor we need to vary some parameters upon which the capacitance depends, as we saw in the previous step the capacitance value depends on the area and the distance been the parallel plates. We will change the area of interaction of two parallel plates to vary the capacitance.
Place the connected capacitor underneath the Heavy Books. Note: This is done in order to flatten the aluminum sheets together and increase capacitance by decreasing distance between the sheets. Step 5: Charge the Capacitor. 1. Turn on the voltage source and wait about 30 seconds for the capacitor to fully charge. See above figure for example.
C = ε * A / d ε: depends on dielectric, A: Area of parallel plates, d: the distance between the plates The formula of capacitance shows that the value of capacitance is dependent on the area of the parallel plates and the distance between them, also it depends on what kind of material is in between them which is known as the dielectric.
In the experiment, our capacitor is similar to an aluminum electrolytic capacitor, except instead of using borax paste for the dielectric, we used a sheet of wax paper. Our capacitor uses the two aluminum foil squares to store positive and negative charges. The charge on the capacitor is proportional to the voltage across the capacitor.