Untitled Flashcards Set

Conductor

Materials in which electric charges move freely (i.e., they have low internal resistance).

Insulator

Materials in which electric charges do not freely move (i.e., they have high internal resistance).

Semiconductor

Materials that lie between conductor and insulator; their electrical properties can change significantly with added foreign atoms.

Coulomb's law

States that two electric charges experience a force between them, which is proportional to the product of the charges and inversely proportional to the square of their separation distance.

Electric Field

An electric charge emits an electric field which points away from a positive charge and towards a negative charge.

Electrostatic Equilibrium

Condition where there is no net motion of charge within a conductor, with the electric field being zero inside.

Potential difference

The change in potential energy per unit charge between two points, defined as the work done to move a charge from one point to another.

Equipotential surface

A surface on which all points are at the same potential; no work is required to move a charge along this surface.

Capacitance

The ratio of the charge stored in a capacitor to the voltage across it, measured in farads (F).

Ohm's Law

States that the voltage difference (∆V) across a conductor is linearly proportional to the current (I) through it, with resistance (R) as the constant of proportionality.

Power

The amount of work done per unit time, related to current and voltage by the equation P = I∆V.

Superconductor

A class of materials that exhibit zero resistance below a certain critical temperature (Tc).

Drift speed

The average speed that electrons move down an electric field in a conductive material.

Electric current

The flow of electric charge through a surface; defined as the rate at which charge flows.

Dielectric

An insulating material placed between the plates of a capacitor to affect its capacitance.

Electric Flux

A measure of the number of electric field lines crossing a given area, defined by ΦE = EA cosθ.

Gauss's Law

States that the electric flux through any closed surface is equal to the net charge inside the surface divided by the permittivity of free space.

Resistance

A measure of how much a material hinders electric current, influenced by temperature and material properties.

Resistivity

The inherent ability of a material to resist electric current; a property of the material itself.

Capacitor

A device that stores electric charge and thus electric potential energy.

Thermistors/Thermocouples

Devices that measure temperature based on resistance changes in their circuit.