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💡AP Physics C: E&M
Key Terms

190 essential vocabulary terms and definitions to know for your AP Physics C: E&M exam

Study AP Physics C: E&M
Practice Vocabulary
💡AP Physics C: E&M
Key Terms by Unit

📚Unit 8 – Electric Charges & Fields: Gauss's Law

8.1 Electric Charge and Electric Force

TermDefinition
attractive forceThe electrostatic force exerted between two objects with opposite charges, pulling them together.
chargeA fundamental property of matter that causes objects to experience forces in electric fields; can be positive or negative.
charge carrierParticles, typically electrons, that carry electric charge and constitute electric current in a conductor.
conductorA material that allows electric charge to move through it, with resistivity that typically increases with temperature.
contact forcesNonfundamental forces such as normal force, friction, and tension that result from the cumulative effect of many electric interactions between particles.
Coulomb's lawThe law stating that the electrostatic force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.
electric forceThe force exerted on a charged object by an electric field, equal to the product of the charge and the electric field strength.
electric permittivityA measure of how easily an electric field can be established in a material.
electric polarizationThe induced rearrangement of electrons by an external electric field, resulting in a separation of positive and negative charges within a material or medium.
electrically neutralA state in which an object or system has equal amounts of positive and negative charge, resulting in no net electric charge.
electrostatic forceThe force between charged objects at rest, described by Coulomb's law and dependent on the magnitudes and signs of the charges.
elementary chargeThe magnitude of charge carried by a single electron or proton, denoted as e, representing the smallest indivisible unit of charge.
free spaceA region of space with no matter, having a constant magnetic permeability value.
gravitational forcesForces that result from the mass of objects and are always attractive in nature.
insulatorMaterials that do not allow electric charge to move freely and can hold charge in fixed positions.
permittivity of free spaceThe electric permittivity of a vacuum, represented by the symbol ε₀, a fundamental constant.
point chargeAn idealized model of a charged object treated as if all its charge is concentrated at a single location in space.
repulsive forceThe electrostatic force exerted between two objects with charges of the same sign, pushing them apart.

8.2 Electric Charge and the Process of Charging

TermDefinition
charge distributionThe spatial arrangement and density of electric charge in a region of space.
conservation of electric chargeThe principle that the total electric charge in an isolated system remains constant over time.
contactDirect physical touching between two systems that can result in the transfer of charge.
electronNegatively charged particles that are the primary charge carriers in most common electrical circuits.
electrostatic forceThe force between charged objects at rest, described by Coulomb's law and dependent on the magnitudes and signs of the charges.
frictionA process by which charge can be transferred between two objects through rubbing or contact.
groundingThe process of electrically connecting a charged object to a much larger neutral system, such as Earth, to neutralize its charge.
induced charge separationThe redistribution of charges within a neutral or charged system caused by the electrostatic force from a nearby charged object, resulting in polarization.
net chargeThe total amount of electric charge in a system, accounting for both positive and negative charges.
polarizationThe process by which a conductor's charge distribution shifts in response to an external electric field while maintaining equipotential conditions.
transfer of chargeThe movement of electric charge from one system to another, typically involving the movement of electrons.

8.3 Electric Fields

TermDefinition
charged conductorMaterials that allow electric charge to move freely throughout their structure and have accumulated electric charge.
charged objectAn object that possesses electric charge and can experience forces from electric and magnetic fields.
electric fieldA vector field that represents the force per unit charge exerted on a test charge at any point in space due to a charge distribution.
electric field lineA line in an electric field diagram whose direction at each point indicates the direction of the electric field, and whose density indicates the relative magnitude of the field.
electric field line diagramA simplified model of an electric field map that uses lines to represent the magnitude and direction of the electric field at any position.
electric forceThe force exerted on a charged object by an electric field, equal to the product of the charge and the electric field strength.
electrostatic equilibriumA state in which excess charge carriers in a conductor have redistributed to the surface, resulting in no net charge in the interior and zero electric field within the conductor.
excess chargeThe net charge that accumulates on or within a conductor or insulator beyond its neutral state.
insulatorMaterials that do not allow electric charge to move freely and can hold charge in fixed positions.
isolated sphereA charged spherical conductor that is far enough from other objects that their electric fields have negligible effects.
net electric fieldThe vector sum of individual electric fields created by multiple charged objects at a given location.
perpendicular to the surfaceThe orientation of the electric field at the surface of a charged conductor, forming a 90-degree angle with the surface.
point chargeAn idealized model of a charged object treated as if all its charge is concentrated at a single location in space.
spherically symmetric charge distributionA charge arrangement on a sphere where the charge is distributed uniformly in all directions from the center.
surface charge distributionThe arrangement of electric charge on the outer surface of a conductor in electrostatic equilibrium.
test chargeA point charge of small enough magnitude that its presence does not significantly affect the electric field it is used to measure.
vector fieldA field in which each point in space is associated with a vector quantity, such as a magnetic field.
vector field mapA representation of a vector field showing the magnitude and direction of the field at various points in space.

8.4 Electric Fields of Charge Distributions

TermDefinition
charge distributionThe spatial arrangement and density of electric charge in a region of space.
electric fieldA vector field that represents the force per unit charge exerted on a test charge at any point in space due to a charge distribution.
integrationA calculus method used to sum infinitesimal contributions to find the total electric field from a continuous charge distribution.
principle of superpositionThe principle that the total electric field is the vector sum of fields produced by individual charges.
symmetryA property of charge distributions that allows simplification of electric field calculations by reducing the number of field components that need to be evaluated.

8.5 Electric Flux

TermDefinition
area vectorA vector perpendicular to the plane of a surface with magnitude equal to the surface area, pointing outward from a closed surface.
closed surfaceA surface that completely encloses a three-dimensional volume with no openings or boundaries.
dot productA mathematical operation between two vectors that produces a scalar result, used to determine the component of one vector in the direction of another.
electric fieldA vector field that represents the force per unit charge exerted on a test charge at any point in space due to a charge distribution.
electric fluxThe measure of the electric field passing through a surface, calculated as the integral of the electric field dot product with the area vector.
surface integralA mathematical integration performed over a two-dimensional surface to calculate the total effect of a vector field across that surface.

8.6 Gauss's Law

TermDefinition
charge densityThe amount of electric charge per unit length, area, or volume of a charge distribution.
charge distributionThe spatial arrangement and density of electric charge in a region of space.
electric fluxThe measure of the electric field passing through a surface, calculated as the integral of the electric field dot product with the area vector.
enclosed chargeThe total electric charge contained within a Gaussian surface.
Gauss's lawA fundamental law of electromagnetism that relates the electric flux through a closed surface to the charge enclosed by that surface.
Gaussian surfaceA three-dimensional, closed surface used in applying Gauss's law, typically chosen to have symmetry matching the charge distribution.
Maxwell's equationsA collection of four fundamental equations that fully describe electromagnetism and the behavior of electric and magnetic fields.

📚Unit 9 – Electric Potential

9.2 Electric Potential

TermDefinition
charge distributionThe spatial arrangement and density of electric charge in a region of space.
chemical processesReactions that cause separation of positive and negative charges, such as those occurring in a battery to create electric potential difference.
displacementA vector quantity representing the change in position from one point to another.
dot productA mathematical operation between two vectors that produces a scalar result, used to determine the component of one vector in the direction of another.
electric fieldA vector field that represents the force per unit charge exerted on a test charge at any point in space due to a charge distribution.
electric field componentThe magnitude of the electric field in a specific direction (such as x, y, or z direction).
electric field vector mapA visual representation showing the direction and magnitude of the electric field at various points in space.
electric potentialThe electric potential energy per unit charge at a point in space, describing the work done per unit charge to move a test charge from a reference point to that location.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts.
equipotential linesLines that connect points of equal electric potential in an electric field; also called isolines of electric potential.
integrationA calculus method used to sum infinitesimal contributions to find the total electric field from a continuous charge distribution.
isoline mapA visual representation showing lines of equal value (such as equal electric potential) across a region.
point chargeAn idealized model of a charged object treated as if all its charge is concentrated at a single location in space.
principle of superpositionThe principle that the total electric field is the vector sum of fields produced by individual charges.
scalar superpositionThe method of adding scalar quantities (electric potentials) from multiple sources to find the total potential at a point.
spatial rate of changeThe rate at which a quantity changes with respect to position or distance in a particular direction.
test chargeA point charge of small enough magnitude that its presence does not significantly affect the electric field it is used to measure.

9.3 Conservation of Electric Energy

TermDefinition
charged objectAn object that possesses electric charge and can experience forces from electric and magnetic fields.
conservation of energyThe principle that the total energy in an isolated system remains constant, with energy transforming between different forms but never being created or destroyed.
electric potentialThe electric potential energy per unit charge at a point in space, describing the work done per unit charge to move a test charge from a reference point to that location.
electric potential energyThe energy stored in a capacitor due to the separation of charge, equal to the work done by an external force to separate the charges.
kinetic energyThe energy of motion possessed by an object.

📚Unit 10 – Conductors and Capacitors

10.1 Electrostatics with Conductors

TermDefinition
charge carrierParticles, typically electrons, that carry electric charge and constitute electric current in a conductor.
charge densityThe amount of electric charge per unit length, area, or volume of a charge distribution.
electric fieldA vector field that represents the force per unit charge exerted on a test charge at any point in space due to a charge distribution.
electric potentialThe electric potential energy per unit charge at a point in space, describing the work done per unit charge to move a test charge from a reference point to that location.
electrostatic equilibriumA state in which excess charge carriers in a conductor have redistributed to the surface, resulting in no net charge in the interior and zero electric field within the conductor.
electrostatic shieldingThe process of surrounding an area with a closed, conducting shell to create a region inside that is free from external electric fields.
equipotential surfaceA surface on which all points have the same electric potential; a conductor in electrostatic equilibrium is an equipotential surface.
excess chargeThe net charge that accumulates on or within a conductor or insulator beyond its neutral state.
ideal conductorA material in which electrons are able to move freely.
polarizationThe process by which a conductor's charge distribution shifts in response to an external electric field while maintaining equipotential conditions.

10.2 Redistribution of Charge Between Conductors

TermDefinition
chargeA fundamental property of matter that causes objects to experience forces in electric fields; can be positive or negative.
charge redistributionThe movement and rearrangement of electric charge between conductors when they are in contact.
conductorA material that allows electric charge to move through it, with resistivity that typically increases with temperature.
electric potentialThe electric potential energy per unit charge at a point in space, describing the work done per unit charge to move a test charge from a reference point to that location.
electrical contactA physical connection between two or more conductors that allows charge to flow between them.
external electric fieldAn electric field created by sources outside the conductor being studied.
groundAn idealized reference point defined as having zero electric potential that can absorb or provide an infinite amount of charge without changing its potential.
induced chargeElectric charge that appears on a conductor due to the influence of an external electric field.

10.3 Capacitors

TermDefinition
capacitanceA measure that relates the magnitude of charge stored on each plate of a capacitor to the electric potential difference between the plates.
constant accelerationUniform acceleration experienced by a charged particle moving between oppositely charged parallel plates in a capacitor.
dielectric constantA dimensionless quantity that relates the electric permittivity of a material to the permittivity of free space, represented by the symbol κ.
electric fieldA vector field that represents the force per unit charge exerted on a test charge at any point in space due to a charge distribution.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts.
electric potential energyThe energy stored in a capacitor due to the separation of charge, equal to the work done by an external force to separate the charges.
Gauss's lawA fundamental law of electromagnetism that relates the electric flux through a closed surface to the charge enclosed by that surface.
parallel-plate capacitorA capacitor consisting of two parallel conducting plates separated by a distance, with a dielectric material that can be inserted between them.
permittivity of free spaceThe electric permittivity of a vacuum, represented by the symbol ε₀, a fundamental constant.
principle of superpositionThe principle that the total electric field is the vector sum of fields produced by individual charges.
surface charge densityThe amount of electric charge per unit area on the surface of a conductor, such as a capacitor plate.

10.4 Dielectrics

TermDefinition
capacitanceA measure that relates the magnitude of charge stored on each plate of a capacitor to the electric potential difference between the plates.
dielectricA material that becomes polarized in the presence of an external electric field, with charges that are not as free to move as in a conductor.
dielectric constantA dimensionless quantity that relates the electric permittivity of a material to the permittivity of free space, represented by the symbol κ.
electric permittivityA measure of how easily an electric field can be established in a material.
external electric fieldAn electric field created by sources outside the conductor being studied.
parallel-plate capacitorA capacitor consisting of two parallel conducting plates separated by a distance, with a dielectric material that can be inserted between them.
permittivity of free spaceThe electric permittivity of a vacuum, represented by the symbol ε₀, a fundamental constant.
polarizedThe state of a dielectric material when its electric charges are displaced or aligned in response to an external electric field.

📚Unit 11 – Electric Circuits

11.1 Electric Current

TermDefinition
chargeA fundamental property of matter that causes objects to experience forces in electric fields; can be positive or negative.
charge carrierParticles, typically electrons, that carry electric charge and constitute electric current in a conductor.
conductorA material that allows electric charge to move through it, with resistivity that typically increases with temperature.
conventional currentThe direction of current defined as the direction in which positive charge would move through a circuit.
currentThe flow of electric charge through a conductor, measured as the amount of charge passing through a cross-section per unit time.
current densityThe amount of electric current flowing per unit cross-sectional area of a conductor; a vector quantity.
drift velocityThe average velocity at which charge carriers move through a conductor in response to an applied electric field.
electric fieldA vector field that represents the force per unit charge exerted on a test charge at any point in space due to a charge distribution.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts.
electromotive forceThe energy per unit charge provided by a source to move charge through a circuit; also called emf.
electronNegatively charged particles that are the primary charge carriers in most common electrical circuits.
resistivityA fundamental property of a material that quantifies how strongly the material opposes the motion of electric charge, depending on the material's atomic and molecular structure.

11.2 Electric Circuits

TermDefinition
circuit schematicA diagram representation used to describe and analyze electric circuits using standardized symbols.
closed circuitA circuit in which charges are able to flow through a complete path.
conventional currentThe direction of current defined as the direction in which positive charge would move through a circuit.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts.
electrical loopA closed path in a circuit through which electric charge can flow.
open circuitA circuit in which charges are not able to flow due to a break in the path.
short circuitA circuit in which charges are able to flow with no change in potential difference.

11.3 Resistance, Resistivity, and Ohm's Law

TermDefinition
conductorA material that allows electric charge to move through it, with resistivity that typically increases with temperature.
cross-sectional areaThe area of the surface perpendicular to the direction of current flow through a conductor.
currentThe flow of electric charge through a conductor, measured as the amount of charge passing through a cross-section per unit time.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts.
Ohm's lawA fundamental relationship stating that current through a conductor is directly proportional to the potential difference across it and inversely proportional to its resistance, expressed as I = ΔV/R.
ohmic materialsMaterials that obey Ohm's law and maintain constant resistance regardless of the current flowing through them.
resistanceThe opposition to the flow of electric current in a circuit, measured in ohms (Ω).
resistivityA fundamental property of a material that quantifies how strongly the material opposes the motion of electric charge, depending on the material's atomic and molecular structure.
resistorA circuit element that dissipates electrical energy and opposes the flow of current, characterized by resistance R.
thermal energyEnergy dissipated in the form of heat when electrical energy is converted within a circuit element.
uniform geometryA resistor with constant cross-sectional area and composition throughout its length.

11.4 Electric Power

TermDefinition
circuit elementA component in an electric circuit, such as a resistor or lightbulb, through which current flows and across which a potential difference exists.
currentThe flow of electric charge through a conductor, measured as the amount of charge passing through a cross-section per unit time.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts.
energy transferThe movement of energy from one location, system, or form to another within an electric circuit.
powerThe rate at which energy is transferred, converted, or dissipated by a circuit element, measured in watts.
resistanceThe opposition to the flow of electric current in a circuit, measured in ohms (Ω).
thermal energyEnergy dissipated in the form of heat when electrical energy is converted within a circuit element.

11.5 Compound Direct Current Circuits

TermDefinition
ammeterAn instrument used to measure electric current at a specific point in a circuit.
currentThe flow of electric charge through a conductor, measured as the amount of charge passing through a cross-section per unit time.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts.
emfThe electromotive force; the potential difference a battery would supply if it were ideal, measured across the terminals when there is no current flowing.
equivalent resistanceThe single resistance value that can replace a combination of resistors in a circuit, producing the same effect on current and voltage.
ideal ammeterA theoretical ammeter with zero resistance that measures current without affecting the circuit.
ideal batteryA theoretical battery with negligible internal resistance that maintains a constant potential difference regardless of the current flowing through it.
ideal voltmeterA theoretical voltmeter with infinite resistance that measures potential difference without allowing charge to flow through it.
ideal wiresTheoretical wires with negligible resistance that do not affect the potential difference in a circuit.
internal resistanceThe resistance within a battery that reduces the potential difference available to the external circuit when current flows through the battery.
nonideal ammeterA real ammeter with some resistance that can alter the properties of the circuit being measured.
nonideal batteryA real battery that has internal resistance and therefore experiences a reduction in terminal voltage when current flows through it.
nonideal voltmeterA real voltmeter with finite resistance that can alter the properties of the circuit being measured.
parallel connectionA circuit configuration in which circuit elements are connected along multiple paths, allowing charge to flow through more than one route with the same potential difference across each path.
resistanceThe opposition to the flow of electric current in a circuit, measured in ohms (Ω).
resistive wiresWires in a circuit that have measurable resistance and can affect the overall circuit behavior.
series connectionA circuit configuration in which circuit elements are connected one after another, so that charge must pass through each element sequentially with no alternative paths available.
terminal voltageThe potential difference measured across the terminals of a battery, which equals the emf minus the voltage drop due to internal resistance when current is flowing.
voltmeterAn instrument used to measure the electric potential difference between two points in a circuit.

11.6 Kirchhoff's Loop Rule

TermDefinition
circuit elementA component in an electric circuit, such as a resistor or lightbulb, through which current flows and across which a potential difference exists.
closed loopA complete path in a circuit that starts and ends at the same point, allowing current to flow continuously.
conservation of energyThe principle that the total energy in an isolated system remains constant, with energy transforming between different forms but never being created or destroyed.
electric potentialThe electric potential energy per unit charge at a point in space, describing the work done per unit charge to move a test charge from a reference point to that location.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts.
Kirchhoff's loop ruleA principle stating that the sum of potential differences across all circuit elements in a single closed loop must equal zero, based on conservation of energy.

11.7 Kirchhoff's Junction Rule

TermDefinition
conservation of electric chargeThe principle that the total electric charge in an isolated system remains constant over time.
currentThe flow of electric charge through a conductor, measured as the amount of charge passing through a cross-section per unit time.
junctionA point in a circuit where two or more conductors meet, allowing current to split or combine.
Kirchhoff's junction ruleA principle stating that the total amount of electric charge entering a junction per unit time must equal the total amount of charge exiting that junction per unit time, based on conservation of electric charge.

11.8 Resistor-Capacitor (RC) Circuits

TermDefinition
asymptotic approachThe behavior of a quantity that approaches a final value over time but never quite reaches it, as seen in RC circuit charging and discharging.
capacitor in parallelCapacitors connected with their plates connected together, where each capacitor experiences the same voltage.
capacitor in seriesCapacitors connected end-to-end in a single path, where the same charge accumulates on each capacitor plate.
charging capacitorA capacitor in a circuit that is accumulating charge, with its charge increasing from zero toward a maximum value over time.
conservation of electric chargeThe principle that the total electric charge in an isolated system remains constant over time.
differential equationA mathematical equation that relates a function to its derivatives, used to describe how quantities change over time.
discharging capacitorA capacitor in a circuit that is losing charge, with its charge decreasing from a maximum value toward zero over time.
electric potential energy stored in the capacitorThe energy stored in the electric field between the capacitor plates, which changes as the capacitor charges or discharges.
equivalent capacitanceThe single capacitance value that can replace a combination of capacitors in a circuit while maintaining the same electrical behavior.
Kirchhoff's loop ruleA principle stating that the sum of potential differences across all circuit elements in a single closed loop must equal zero, based on conservation of energy.
potential difference across a capacitorThe voltage between the plates of a capacitor, which changes over time during charging and discharging and reaches a constant value at steady state.
RC circuitA circuit containing a resistor and capacitor in combination, where the charge and current change over time as the capacitor charges or discharges.
steady stateA condition reached after a long time interval where circuit quantities no longer change with time.
time constantA characteristic parameter that measures how quickly a circuit reaches steady state, calculated differently for RC and LR circuits.

📚Unit 12 – Magnetic Fields & Electromagnetism

12.1 Magnetic Fields

TermDefinition
bar magnetA permanent magnet with distinct north and south poles that produces closed-loop magnetic field lines.
diamagnetismA property of all materials in which their electronic structure creates a usually weak alignment of dipole moments opposite to an external magnetic field.
external magnetic fieldA magnetic field applied to a material from an outside source.
ferromagnetic materialsMaterials such as iron, nickel, and cobalt that can be permanently magnetized by an external field through alignment of magnetic domains or atomic magnetic dipoles.
free spaceA region of space with no matter, having a constant magnetic permeability value.
Gauss's law for magnetismMaxwell's second equation stating that magnetic field lines form closed loops and there are no magnetic monopoles.
induced magnetismA system property resulting from the alignment of magnetic dipoles within a material caused by an external magnetic field.
magnetic dipoleA system with a north and south magnetic pole that results from the circular or rotational motion of electric charges, such as moving electrons in atoms.
magnetic domainsRegions within ferromagnetic materials where atomic magnetic dipoles are aligned in the same direction.
magnetic fieldA vector field that determines the magnetic force exerted on moving electric charges, electric currents, or magnetic materials.
magnetic field linesLines that represent the direction and strength of a magnetic field, forming closed loops that never begin or end.
magnetic forceThe force exerted on a moving charged particle or current-carrying conductor in the presence of a magnetic field.
magnetic monopoleA hypothetical isolated magnetic charge that does not exist in nature; magnetic fields are always produced by dipoles.
magnetic permeabilityA property of a material that describes how easily a magnetic field can be established within it; affects the inductance of a solenoid.
magnetic polesThe regions at the ends of a magnetic dipole where magnetic effects are strongest; poles of the same polarity repel while opposite poles attract.
magnetizationThe process by which a material becomes magnetized or the degree to which a material is magnetized in response to an external magnetic field.
Maxwell's equationsA collection of four fundamental equations that fully describe electromagnetism and the behavior of electric and magnetic fields.
north poleOne end of a magnetic dipole from which external magnetic field lines point away.
paramagnetic materialsMaterials such as aluminum, titanium, and magnesium that interact weakly with an external magnetic field and do not retain alignment after the field is removed.
permanent magnetismA system property resulting from the alignment of magnetic dipoles within a material that persists without an external magnetic field.
south poleOne end of a magnetic dipole to which external magnetic field lines return.
vacuum permeabilityThe constant value of magnetic permeability in free space, denoted as μ₀, that appears in equations representing physical relationships.
vector fieldA field in which each point in space is associated with a vector quantity, such as a magnetic field.
vector field mapA representation of a vector field showing the magnitude and direction of the field at various points in space.

12.2 Magnetism and Moving Charges

TermDefinition
charged objectAn object that possesses electric charge and can experience forces from electric and magnetic fields.
conductorA material that allows electric charge to move through it, with resistivity that typically increases with temperature.
cross-productA mathematical operation between two vectors that produces a third vector perpendicular to both, with magnitude equal to the product of their magnitudes and the sine of the angle between them.
Hall effectThe phenomenon where a potential difference is created across a conductor perpendicular to both the direction of current flow and an applied magnetic field.
Lorentz forceThe force exerted on a moving charged object by a magnetic field, given by F_B = q(v × B).
magnetic fieldA vector field that determines the magnetic force exerted on moving electric charges, electric currents, or magnetic materials.
moving charged objectAn object possessing electric charge that is in motion, producing a magnetic field in the surrounding space.
perpendicularAt a 90-degree angle; the magnetic field direction is perpendicular to both the velocity vector and position vector of a moving charged object.
position vectorA vector drawn from a moving charged object to a point in space, used to determine the direction and magnitude of the magnetic field at that point.
right-hand ruleA method for determining the direction of the magnetic field produced by a moving charged object by pointing the thumb in the direction of velocity and curling fingers to show the field direction.
velocityThe rate and direction of motion of an object.

12.3 Magnetic Fields of Current-Carrying Wires and the Biot-Savart Law

TermDefinition
Biot-Savart lawA fundamental law that defines the magnitude and direction of the magnetic field created by a small segment of electrical current.
circular loop of wireA wire bent into a circular shape through which current flows, creating a magnetic field with specific properties at its center.
concentric circlesCircles that share the same center point; the magnetic field lines around a current-carrying wire form concentric circles centered on the wire.
current-carrying wireA conductor through which electric current flows, creating a magnetic field in the surrounding space.
magnetic fieldA vector field that determines the magnetic force exerted on moving electric charges, electric currents, or magnetic materials.
magnetic field vectorsArrows representing the magnitude and direction of the magnetic field at specific points in space around a current-carrying wire.
magnetic forceThe force exerted on a moving charged particle or current-carrying conductor in the presence of a magnetic field.

12.4 Ampère's Law

TermDefinition
Ampère's lawA fundamental equation that relates the magnitude of the magnetic field to the electric current enclosed by a closed imaginary path.
Amperian loopA closed imaginary path drawn around a current-carrying conductor used to apply Ampère's law.
changing electric fieldA time-varying electric field that generates a magnetic field according to Maxwell's equations.
conductive cylinderA cylindrical conductor carrying current to which Ampère's law can be applied to determine the magnetic field.
current densityThe amount of electric current flowing per unit cross-sectional area of a conductor; a vector quantity.
current-carrying wireA conductor through which electric current flows, creating a magnetic field in the surrounding space.
electric currentThe flow of electric charge through a conductor, which generates a magnetic field.
magnetic fieldA vector field that determines the magnetic force exerted on moving electric charges, electric currents, or magnetic materials.
Maxwell's additionThe modification to Ampère's law stating that a changing electric field creates a magnetic field in addition to the magnetic field created by electric current.
Maxwell's equationsA collection of four fundamental equations that fully describe electromagnetism and the behavior of electric and magnetic fields.
moving charge carrierAn electric charge in motion that generates a magnetic field around it.
principle of superpositionThe principle that the total electric field is the vector sum of fields produced by individual charges.
solenoidA coil of wire wound in a tight, helical pattern that produces a uniform magnetic field when current flows through it.

📚Unit 13 – Electromagnetic Induction

13.1 Magnetic Flux

TermDefinition
area vectorA vector perpendicular to the plane of a surface with magnitude equal to the surface area, pointing outward from a closed surface.
closed surfaceA surface that completely encloses a three-dimensional volume with no openings or boundaries.
dot productA mathematical operation between two vectors that produces a scalar result, used to determine the component of one vector in the direction of another.
magnetic fieldA vector field that determines the magnetic force exerted on moving electric charges, electric currents, or magnetic materials.
magnetic fluxThe measure of the total magnetic field passing through a surface, calculated as the dot product of the magnetic field vector and the area vector.
surface integralA mathematical integration performed over a two-dimensional surface to calculate the total effect of a vector field across that surface.

13.2 Electromagnetic Induction

TermDefinition
electromagnetic wavesWaves consisting of oscillating electric and magnetic fields that propagate through space at a constant speed in free space.
Faraday's lawThe principle that describes the relationship between a changing magnetic flux and the induced emf in a system, expressed as ε = -∆ΦB/∆t.
induced electric potential differenceThe voltage generated in a conductor or circuit due to a change in magnetic flux through it.
induced emfThe electromotive force generated in a conductor or circuit as a result of a change in magnetic flux.
Lenz's lawThe principle that states an induced emf generates a current that creates a magnetic field opposing the change in magnetic flux.
magnetic fluxThe measure of the total magnetic field passing through a surface, calculated as the dot product of the magnetic field vector and the area vector.
Maxwell's equationsA collection of four fundamental equations that fully describe electromagnetism and the behavior of electric and magnetic fields.
right-hand ruleA method for determining the direction of the magnetic field produced by a moving charged object by pointing the thumb in the direction of velocity and curling fingers to show the field direction.
solenoidA coil of wire wound in a tight, helical pattern that produces a uniform magnetic field when current flows through it.

13.3 Induced Currents and Magnetic Forces

TermDefinition
charge carrierParticles, typically electrons, that carry electric charge and constitute electric current in a conductor.
conductive loopA closed path made of conducting material through which electric current can flow.
conductorA material that allows electric charge to move through it, with resistivity that typically increases with temperature.
induced currentAn electric current generated in a conductor due to a change in magnetic flux through a circuit.
induced emfThe electromotive force generated in a conductor or circuit as a result of a change in magnetic flux.
magnetic fieldA vector field that determines the magnetic force exerted on moving electric charges, electric currents, or magnetic materials.
magnetic fluxThe measure of the total magnetic field passing through a surface, calculated as the dot product of the magnetic field vector and the area vector.
magnetic forceThe force exerted on a moving charged particle or current-carrying conductor in the presence of a magnetic field.
resistanceThe opposition to the flow of electric current in a circuit, measured in ohms (Ω).
rotational accelerationThe angular acceleration of an object about a fixed axis due to an applied torque.
translational accelerationThe acceleration of an object's center of mass in a straight line due to an applied force.

13.4 Inductance

TermDefinition
Faraday's lawThe principle that describes the relationship between a changing magnetic flux and the induced emf in a system, expressed as ε = -∆ΦB/∆t.
induced emfThe electromotive force generated in a conductor or circuit as a result of a change in magnetic flux.
inductanceThe tendency of a conductor to oppose a change in electrical current.
inductorA circuit element that stores electrical energy in a magnetic field and opposes changes in current.
magnetic field energyEnergy stored in the magnetic field generated by current flowing through an inductor.
magnetic permeabilityA property of a material that describes how easily a magnetic field can be established within it; affects the inductance of a solenoid.
solenoidA coil of wire wound in a tight, helical pattern that produces a uniform magnetic field when current flows through it.

13.5 Circuits with Resistors and Inductors (LR Circuits)

TermDefinition
asymptoteA limiting value that a quantity approaches but never reaches, determined by the initial conditions of an LR circuit.
differential equationA mathematical equation that relates a function to its derivatives, used to describe how quantities change over time.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts.
energy dissipationThe process by which a resistor converts electrical energy stored in an inductor into heat as current changes.
exponential functionA mathematical function describing how current, voltage, and energy in an LR circuit change with time, with asymptotic behavior.
induced emfThe electromotive force generated in a conductor or circuit as a result of a change in magnetic flux.
inductorA circuit element that stores electrical energy in a magnetic field and opposes changes in current.
Kirchhoff's loop ruleA principle stating that the sum of potential differences across all circuit elements in a single closed loop must equal zero, based on conservation of energy.
LR circuitA circuit containing a resistor and inductor in series with a power source, where current changes are governed by both resistance and inductance.
resistorA circuit element that dissipates electrical energy and opposes the flow of current, characterized by resistance R.
steady stateA condition reached after a long time interval where circuit quantities no longer change with time.
time constantA characteristic parameter that measures how quickly a circuit reaches steady state, calculated differently for RC and LR circuits.
transient behaviorThe time-dependent behavior of an LR circuit immediately after a switch is opened or closed, before reaching steady state.

13.6 Circuits with Capacitors and Inductors (LC Circuits)

TermDefinition
angular frequencyThe rate of oscillation of a periodic system, measured in radians per second, denoted by ω.
capacitorA circuit element that stores electrical energy in an electric field between two conducting plates.
conservation of energyThe principle that the total energy in an isolated system remains constant, with energy transforming between different forms but never being created or destroyed.
differential equationA mathematical equation that relates a function to its derivatives, used to describe how quantities change over time.
inductorA circuit element that stores electrical energy in a magnetic field and opposes changes in current.
LC circuitA circuit containing only a capacitor and an inductor that can oscillate, exchanging energy between electric and magnetic fields.
simple harmonic motionPeriodic motion in which an object oscillates about an equilibrium position with acceleration proportional to its displacement.

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