Electric Circuits Vocabulary

Flashcards covering key vocabulary from the Electric Circuits lecture notes.

Electromagnetism

One of the four fundamental interactions in nature, responsible for most phenomena in daily life above the nuclear scale, except for gravity.

Electric Field

A field in classical physics, similar to gravitational fields, where the source is a charge, and forces are exerted upon other charges.

Electric Potential

The amount of electric potential energy (work) per unit of charge that would be possessed by a charged object if placed within an electric field at a given location.

Electric Potential Difference

The difference in electric potential between two different locations within an electric field; the value measured by a voltmeter in an electric circuit.

Internal Circuit

The part of an electric circuit where energy is being supplied to the charge, such as the portion containing electrochemical cells in a battery-powered circuit.

External Circuit

The part of an electric circuit where charge is moving outside the cells through the wires, from the high potential terminal to the low potential terminal.

Battery EMF

The total potential drop across the external circuit as the charge moves from the positive terminal back to 0 volts at the negative terminal.

Electric Current (I)

The rate of charge flow past a given point in an electric circuit, measured in amperes (coulombs/second).

Drift Velocity

The average velocity of a charge carrier in a conductor due to an electric field.

Electric Potential Difference (ΔV)

Voltage; the work per unit charge to move a charge from one point to another.

Electromotive Force (EMF) (E)

The potential generated or supplied by a battery or by induction, representing energy gain per unit charge.

Electric Resistance (R)

The opposition to the flow of electric current in a conductor, measured in ohms (Ω).

Resistivity (ρ)

A measure of a material's ability to oppose the flow of electric current, inverse of conductivity (σ), measured in ohm-meters (Ωm).

Internal Resistance (r)

The resistance within a cell that causes energy loss per unit charge when current flows through it.

Electrical Potential Energy (U)

Energy lost as work is done when a charge Q is moved from higher potential to lower potential of a resistor; also, energy gained by a charge moving against an electric field inside a power source.

Electrical Power (P)

The rate of change of potential energy; the rate at which electrical energy is converted to heat, measured in watts (W).

Ohmic Conductor

A conductor, like a metal, that has a linear voltage-current relationship over a large range of applied EMF and obeys Ohm's law.

Non-Ohmic Conductor

A conductor, like a semiconductor, that has a non-linear voltage-current relationship.

Superconductor

A material whose electrical resistance decreases gradually as temperature is lowered and goes virtually to zero below a critical temperature (Tc).

Series Circuit

A circuit where there is only one path for the electricity to flow; the same current flows through each component.

Parallel Circuit

A circuit that has two or more paths for the carriers to flow; each component will have different carriers flowing through it.

Passive Devices

Components that do not generate energy, but can store it or dissipate it, such as resistors, inductors, capacitors, and transformers.

Capacitor

A device consisting of two conducting plates separated by an insulator (dielectric), used to store energy electrostatically.

Inductor

A passive device that resists changes in the electric current passing through it, usually a wounded coil of wire, which stores energy in the form of a magnetic field.

Kirchhoff’s Current Law (K1)

The amount of current that enters a node is equal to the amount of current leaving a node; also known as the junction rule.

Kirchhoff’s Voltage Law (K2)

In any closed loop circuit, the total algebraic EMF supplied will always equal the algebraic sum of all the potential drops within the loop; also known as the loop rule.