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📚AP Physics 2 Unit 11 Vocabulary

55 essential vocabulary terms and definitions for Unit 11 – Electric Circuits

Study Unit 11
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📚Unit 11 – Electric Circuits
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📚Unit 11 – Electric Circuits

11.1 Electric Current

TermDefinition
chargeA fundamental property of matter that can be positive or negative, determining how objects interact electromagnetically.
charge carrierParticles that carry electric charge through a medium, such as electrons in a wire.
conventional currentThe direction of electric current flow defined as the movement of positive charges from the positive terminal to the negative terminal of a power source.
currentThe flow of electric charge through a conductor, measured in amperes (A).
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts; also called voltage.
electromotive forceThe energy per unit charge provided by a source such as a battery to move charge through a circuit; abbreviated as emf (ε).
electronNegatively charged particles that serve as the primary charge carriers in most common electrical circuits.

11.2 Simple Circuits

TermDefinition
circuitA closed or open path composed of electrical loops and circuit elements through which electric charge may flow.
circuit elementA component in an electric circuit, such as a resistor or bulb, through which current flows and across which a potential difference exists.
circuit schematicA diagram used to represent and analyze electric circuits using standardized symbols for circuit elements.
closed circuitA circuit in which charges are able to flow through a complete path.
conventional currentThe direction of electric current flow defined as the movement of positive charges from the positive terminal to the negative terminal of a power source.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts; also called voltage.
electrical loopA closed path in a circuit through which charges may 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 flow with no change in potential difference.

11.3 Resistance, Resistivity, and Ohm's Law

TermDefinition
chargeA fundamental property of matter that can be positive or negative, determining how objects interact electromagnetically.
conductorA material through which electric charge can move, with resistivity that typically increases with temperature.
cross-sectional areaThe area of a cross-section of a conductor, which is inversely proportional to its resistance.
currentThe flow of electric charge through a conductor, measured in amperes (A).
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts; also called voltage.
electrical characteristicsThe properties of circuit elements that describe how they respond to and affect electric current and voltage, including resistance and conductivity.
Ohm's lawThe relationship stating that current through a conductive element is directly proportional to the potential difference across it and inversely proportional to its resistance (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 through a material or circuit element.
resistivityAn intrinsic property of a material that measures its resistance to electric current flow; remains constant for ohmic materials regardless of temperature.
resistorCircuit elements designed to provide resistance to current flow and convert electrical energy into thermal energy.
thermal energyThe energy produced when a resistor converts electrical energy, which can increase the temperature of the resistor and its surroundings.

11.4 Electric Power

TermDefinition
brightnessThe luminous intensity of a bulb, which increases with the power dissipated by the bulb.
circuit elementA component in an electric circuit, such as a resistor or bulb, through which current flows and across which a potential difference exists.
currentThe flow of electric charge through a conductor, measured in amperes (A).
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts; also called voltage.
energy transferThe movement of energy into, out of, or within an electric circuit through the work done by electric forces.
powerThe rate at which energy is transferred, converted, or dissipated in an electric circuit, measured in watts.

11.6 Kirchhoff's Loop Rule

TermDefinition
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 not being created or destroyed.
electric potentialA scalar quantity that represents the electric potential energy per unit charge at a point in space, measured in volts.
electric potential differenceThe difference in electric potential energy per unit charge between two points in a circuit, measured in volts; also called voltage.
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 chargeThe principle that the total electric charge in an isolated system remains constant over time.
currentThe flow of electric charge through a conductor, measured in amperes (A).
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 electric charge entering a junction per unit time equals the total charge exiting that junction per unit time, based on conservation of electric charge.

11.8 Resistor-Capacitor (RC) Circuits

TermDefinition
capacitor in parallelCapacitors connected with all positive plates connected together and all negative plates connected together, where the equivalent capacitance equals the sum of individual capacitances.
capacitor in seriesCapacitors connected end-to-end in a single path, where the same charge accumulates on each capacitor and the equivalent capacitance is less than the smallest individual capacitance.
charging capacitorA capacitor in a circuit that is accumulating charge on its plates, with increasing potential difference and decreasing current over time until reaching steady state.
conservation of chargeThe principle that the total electric charge in an isolated system remains constant over time.
discharging capacitorA capacitor in a circuit that is releasing stored charge from its plates, with decreasing potential difference, charge, and current over time until reaching steady state.
electric potential energy stored in the capacitorThe energy stored in a capacitor due to the separation of charge on its plates, which changes during charging and discharging and approaches a constant value at steady state.
equivalent capacitanceThe single capacitance value that can replace a collection of capacitors in a circuit while maintaining the same electrical behavior.
fully chargedThe state of a capacitor after a long charging time when it has reached maximum potential difference and zero current flows in the circuit branch containing it.
potential difference across a capacitorThe voltage between the plates of a capacitor, which changes over time during charging and discharging and asymptotically approaches a steady-state value.
RC circuitA circuit containing a resistor and capacitor in combination, where the capacitor charges or discharges through the resistor over time.
steady stateA condition reached after a long time interval where the potential difference across a capacitor and current in the circuit branch remain constant.
time constantA measure of how quickly a capacitor charges or discharges in an RC circuit, defined as τ = R_eq × C_eq, representing the time for charge to reach approximately 63% of final value when charging or 37% of initial value when discharging.