M7 Electric Current and DC Circuits

Flashcards covering key vocabulary and concepts from College Physics 2 focusing on electric current, circuits, and related laws.

Electric Current

The rate of flow of electrons in a circuit, measured in Amperes (A).

Ohm's Law

States that the current across a conductor between two points is directly proportional to the voltage across the two points, represented as I = V/R.

Current Density

The amount of electric current flowing per unit cross-sectional area of a material, represented as J = I/A.

Drift Velocity

The average velocity of charge carriers, directed opposite to the electric field for electrons.

Resistivity

A characteristic property of a material that indicates how strongly it resists the flow of electric current, represented by the Greek letter rho (ρ).

Resistance

A measure of the opposition to current flow in an electrical circuit, measured in Ohms (Ω).

Ampere

The unit of electric current, defined as one coulomb of charge passing a point in a conductor per second.

Coulomb

The unit of electric charge, equivalent to the charge transported by a constant current of one ampere in one second.

Closed Circuit

A complete electrical loop allowing current to flow, as opposed to an open circuit where the current flow is interrupted.

Series Circuit

An electric circuit in which components are arranged in a chain, so the current has only one path to follow.

Parallel Circuit

An electric circuit where multiple paths for current flow are available; the same voltage is applied across each branch.

Kirchhoff's Voltage Law (KVL)

States that the algebraic sum of the potential differences in any closed loop must equal zero.

Kirchhoff's Current Law (KCL)

States that the algebraic sum of currents entering a junction is equal to the sum of the currents leaving the junction.

Electromotive Force (emf)

The energy provided per charge by a power source, measured in Volts (V).

Internal Resistance

The resistance within a source of emf that causes energy dissipation as heat.

Capacitor

An electrical component used to store electric charge temporarily in an electric field.

Time Constant (τ)

The time it takes for the voltage across a capacitor to either charge or discharge to about 63% of its maximum value.