[Science 1] Electricity Flashcards
What is the Electrostatic/Coulomb force?
The force of repulsion or attraction between two like and unlike charges
Why does most matter act as if there is no electric charge at all?
Because ordinary matter has zero net charge (excess charge)
In what conditions does static electricity form?
Disruption of the balance between protons and electrons
What is charge?
Amount of electrons
What is the unit of charge?
Coulomb (C)
What is an object that can easily gain or lose electrons?
Conductor
Why are metals good conductors?
Free electrons (allows electrons to move freely through the material)
What is a net negative charge?
More electrons than protons - - & vice versa
What is an object that does not easily gain or lose electrons?
Insulator (ex. glass, plastic)
What does “being polarised” mean and for what types of things does this phenomena occur?
-Occurs in insulators
-Instead of gaining or losing electrons, the charges within the insulator shift slightly. This causes one side to become more positive and the other side more negative without changing the overall charge.
What is the purpose of an electroscope? What kind of environment are they in?
-Detect the presence of an electric charge on a body
-Isolated from the environment to prevent charge loss
What can we use to determine if something is positively or negatively charged (by relative position of the item)?
Electrification series
What happens if a positive rod moves closer to the electroscope?
The electrons on the metal disk would move towards the rod(Protons on the metal desk would still stay where they are due to the strong nuclear force). And since the protons originally on the leaves does not have electrons to cancel them out, the protons repulse, and the leaves becomes positive, moving it further apart. If this happens, it’ll mean that it’s a positively charged electroscope.
What happens if a negative rod moves closer to the electroscope?
The electrons on the metal disk would go down towards the leaves. However, since there are still protons left in the leaves (since protons remain fixed because of the strong nuclear force), the electrons and protons would cancel out and the leaves move closer together.
How are electrical shocks from static electricity caused?
Electrons jumping from one charged object to another due to an imbalance of electrons
What is voltage?
Pressure that pushes electricity to flow in a certain direction (aka electro-motive force)
What is the flow of electrons called?
Electric Current
What is electric discharge
Quick release of built-up electric charge from an object, causing the side where there are excess electrons (negative charge) to move towards the side where there is a lack of electrons (positive charge)
What was the idea in the conventional current?
An original assumption that people had, where they thought that electric currents flowed from + to -, before electrons were discovered
What is resistance?
Force that electrons experience when bumping into particles in; for example, air (More resistance —> less current flow; electrons slow down)
What is the unit of resistance?
Ohm (Ω)
What is the unit of current?
Ampere (A)