Electricity, Magnetism, and Electromagnetism

Comprehensive vocabulary flashcards covering electrostatics, electrodynamics, circuits, magnetism, and electromagnetism from Chapter 5 lecture notes and slides.

Electrostatics

The study of stationary electric charges.

Electrification

The process that occurs when an object gains either a net positive or a net negative charge through contact, friction, or induction.

Electrification by Friction

Electrification that occurs when electrons are rubbed off one object and deposited on another, giving one a negative charge and leaving the other positively charged (e.g., rubbing a balloon on hair).

Electrification by Contact

Electrification that occurs when a charged object physically touches an uncharged object and transfers electric charge (e.g., a charged fingertip touching a metal doorknob and creating a spark).

Electrification by Induction

The process by which an uncharged metallic object experiences a shift of electrons when brought into the electric field of a charged object without physical contact, utilized in the design of the x-ray tube.

Law of Electrostatic Attraction and Repulsion

The fundamental electrostatic law stating that unlike charges attract and like charges repel.

Law of Electrostatic Charge Distribution

The electrostatic law stating that electric charge is uniformly distributed either throughout the volume of a material or across its surface.

Law of Electrostatic Concentration

The electrostatic law stating that the electric charge of a conductor is concentrated along the sharpest curvature of its surface.

Coulomb's Law

The law stating that the electrostatic force between two charges is directly proportional to the product of their quantities (charges) and inversely proportional to the square of the distance between them.

Electric Potential

The ability to do work due to the separation of electric charges, measured in units of joule per coulomb, or volt ($\text{V}$).

Electric Potential Energy

The energy possessed by electric charges by virtue of their state or position, such as like electric charges positioned close together that can do work when repelling one another.

Electrodynamics

The study of electric charges in motion.

Electricity

The continuous flow of electrons along the surface of a conductor.

Conductor

Any substance or material through which electrons easily flow.

Insulator

Any material that does not allow, restricts, or prevents electron flow.

Semiconductor

A material that under some conditions behaves as an insulator and in other conditions behaves as a conductor.

Superconductor

A material that exhibits no electrical resistance below a critical temperature.

Electric Current

The rate of flow of electricity

• defined as charge quantity divided by time, which exists when there is an electric potential difference between two charged objects and a suitable medium.

Ampere ($\text{A}$)

The standard unit of electric current, where one ampere represents the flow of $6.3 \times 10^{15}$ electrons.

Milliampere ($\text{mA}$)

A unit of electric current equal to one-thousandth of an ampere ($10^{-3}\,\text{A}$).

Electric Circuit

A closed loop where a conductor wire leaving a battery or generator passes through devices being operated and returns to the source.

Source of EMF (Electromotive Force)

A circuit component (such as a battery or generator) that provides the electric potential difference ($-/+$) required to drive electric current.

Resistor

A circuit component or operated device that inhibits or opposes the flow of electrons.

Electric Resistance

The opposition to the flow of electric current; it increases with longer conductor length, narrower diameter, and poorer conducting material.

Series Circuit

An electric circuit in which all devices and circuit elements are connected sequentially in a row within the same line or wire.

Parallel Circuit

An electric circuit that uses branches of wire splitting off from the original wire to connect across each device or plug individually.

Series Circuit Resistance Rule

The rule stating that the total resistance in a series circuit is equal to the sum of the individual resistances ($R_{\text{total}} = R_1 + R_2 + R_3 + \dots$).

Series Circuit Current Rule

The rule stating that the electric current through each circuit element in a series circuit is identical and equal to the total circuit current ($I_{\text{total}} = I_1 = I_2 = I_3 = \dots$).

Series Circuit Voltage Rule

The rule stating that the sum of the voltages across each circuit element in a series circuit is equal to the total circuit voltage ($V_{\text{total}} = V_1 + V_2 + V_3 + \dots$).

Parallel Circuit Current Rule

The rule stating that the sum of the currents through each individual branch or circuit element in a parallel circuit equals the total circuit current ($I_{\text{total}} = I_1 + I_2 + I_3 + \dots$).

Parallel Circuit Voltage Rule

The rule stating that the voltage across each circuit element in a parallel circuit is the same and is equal to the total circuit voltage ($V_{\text{total}} = V_1 = V_2 = V_3 = \dots$).

Parallel Circuit Resistance Rule

The rule stating that the total resistance in a parallel circuit is the inverse of the sum of the reciprocals of each individual resistance ($\frac{1}{R_{\text{total}}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \dots$).

Ohm's Law

The fundamental formula governing circuit behavior: $V = IR$, where $V$ is electric potential in volts, $I$ is current in amperes, and $R$ is resistance in ohms.

Electric Power

The rate at which electrical work is done, measured in watts ($\text{W}$) and calculated by the formula $P = IV$, where $I$ is current in amperes and $V$ is electric potential in volts.

Watt ($\text{W}$)

The unit of electric power, defined as one ampere ($\text{A}$) of current flowing through an electric potential of one volt ($\text{V}$).

Magnetism

The physical phenomenon created by charged particles in motion, forming one half of the unified phenomenon of electromagnetism.

Magnetic Field

The field of force created perpendicular to the motion of any moving charged particle.

Electron Spin

The rotational motion of an electron that produces a magnetic field with a north pole and a south pole, behaving in a dipolar or bipolar manner.

Magnetic Field Lines

The imaginary lines that map a magnetic field, which always form complete, closed loops.

Magnetic Permeability

The ability of a material to attract and concentrate lines of magnetic field intensity.

Magnetic Susceptibility

The degree to which a substance or material can be magnetized when placed in an external magnetic field.

Nonmagnetic Material

A class of material that is unaffected by a magnetic field, such as glass.

Diamagnetic Material

A class of material that is weakly repelled by a magnetic field, such as water.

Ferromagnetic Material

A class of material strongly attracted to a magnetic field that can be magnetized permanently or temporarily, such as iron.

Paramagnetic Material

A class of material that is weakly attracted to a magnetic field, such as gadolinium.

Principal Types of Magnets

The three primary classifications of magnets: natural magnets, artificial magnets, and electromagnets.

Law of Magnetic Poles

The law stating that every magnet has a north and south pole; like poles repel and unlike poles attract, with force varying directly as pole strengths and inversely as the square of the distance between them.

Magnetic Induction

The process whereby a ferromagnetic material placed near an intense magnetic field has its lines of induction altered and becomes temporarily magnetized.

Tesla ($\text{T}$)

The standard SI unit of magnetic field strength, where $1\,\text{T} = 10{,}000\,\text{G}$.

Gauss ($\text{G}$)

An older, non-SI unit of magnetic field strength, where $10{,}000\,\text{G} = 1\,\text{T}$.

Electromagnetism

The single physical phenomenon encompassing electricity and magnetism as interconnected aspects of the same force.

Solenoid

A helical coil of wire that concentrates magnetic field lines within its loop when carrying electric current.

Electromagnet

A current-carrying coil of wire (solenoid) wrapped around an iron core to amplify and intensify the magnetic field.

Oersted's Discovery

The experimental finding that an electric current in a wire deflects a compass needle, showing that electricity produces mechanical motion and providing the basis for the electric motor.

Electromagnetic Induction

The production of an electric current in a circuit when a conductor experiences a changing or moving magnetic field.

Faraday's Law

The first law of electromagnetic induction stating that a static magnetic field cannot induce current, but a changing magnetic field induces a current whose size depends on field strength, field velocity, conductor angle, and number of turns.

Ammeter

A measuring instrument used in an electric circuit to detect, indicate, and quantify electric current.

Induction Motor

The type of motor used to rotate the anode of an x-ray tube, operating on the principles of electromagnetic induction.

Stator

The stationary component of an induction motor composed of stationary electromagnets located around the exterior of the rotor.

Rotor

The rotating inner component of an induction motor located in the middle of the stators, constructed of an iron core surrounded by coils.

Transformer

An electrical device that alters the intensity of alternating voltage and current via mutual induction, utilizing interacting magnetic fields and requiring alternating current (AC).

Transformer Law

The law stating that the difference in voltage induced in the secondary coil depends directly on the ratio of the number of turns of wiring in the primary and secondary coils.

Closed-Core Transformer

A transformer configuration where primary and secondary coils are wound around a square or circular iron core providing a continuous path for the magnetic field.

Shell-Type Transformer

A transformer configuration in which both primary and secondary windings are wrapped around a central core for maximum efficiency.

Autotransformer

A transformer consisting of an iron core with only one winding of wire around it, designed to vary both voltage and current.