What causes electricity to occur?

Answer 1

Electricity can be a simple as charge movement. That's a basic definition, and it can be expanded from there. But in its essential form, anything that can generate a voltage can "cause electricity" as a result. Let's look at things that generate a voltage. Triboelectric effect, a form of contact electrification, generates a voltage and causes charge movement by the simple act of separating two materials. (Anyone who takes a piece of plastic wrap off a roll causes this. That's where the static charge on the wrap comes from, and that's why it is a challenge to "make it behave" when trying to put it on something. Piezoelectric effect is the generation of voltage by applying mechanical energy to certain crystals or possibly ceramics. Pyroelectric effect. Heat causes charge movement, and this phenomena is directly related to Piezoelectric effect. Thermionic effect causes charge movement in response to thermal energy, to heat, but is different from pyroelectric effect. Photoelectric effect is the generation of a voltage by the application of photons (light) to a photosensitive material. Electrochemical action is what batteries are all about. Electromagnetic induction is extremely common. We use it everywhere in motors and generators as well as a broad variety of other things. Got links if you want them. They are to related articles posted by our friends at Wikipedia, where knowledge is free.