2007-02-08 14:09:40 · 3 answers · asked by rajk_91 1 in Science & Mathematics ➔ Engineering
Aluminum is used for the electrodes, and a very thin layer of Al2O3 forms on the surface as a dielectric, formed in an electrolyte by a small current. If the voltage is reversed, the aluminum oxide dissolves.
Make your own: two pieces of aluminum foil, with some paper between, in a solution of boric acid works. Boric acid is a mild but cumulative poison... use care.
2007-02-08 15:25:05 · answer #1 · answered by Anonymous · 0⤊ 0⤋
It's because of the construction technique used. They found a way to make large value capacitors very small, but the side effect is that they conduct current if you reverse the voltage. Many times they explode if you put a reverse voltage on them.
2007-02-08 22:44:49 · answer #2 · answered by vrrJT3 6 · 0⤊ 0⤋
Because polarity is important in some circuits.
2007-02-16 21:53:41 · answer #3 · answered by Some Guy 3 · 0⤊ 0⤋