(69) AP Physics 2 Circuits Review

Current

The rate of flow of charge in a circuit, often represented as ΔQ/ΔT.

Electro-motive force (EMF)

The potential difference provided by a battery that drives the current in a circuit.

Resistance (R)

A measure of the opposition to current flow in a circuit, dependent on the material, length, and cross-sectional area.

Resistivity (ρ)

A property of a material that quantifies how strongly it resists the flow of electric current, constant for a given material.

Ohm's law

The principle stating that the current (I) in a circuit is directly proportional to the voltage (V) and inversely proportional to the resistance (R), given by the formula V=IR.

Series circuit

A circuit configuration where components are connected end-to-end, resulting in the same current flowing through each component.

Parallel circuit

A circuit configuration where components are connected across common points, resulting in the same voltage across each component but different currents.

Kirchhoff's junction rule

The principle that the total current entering a junction must equal the total current leaving the junction in an electrical circuit.

Kirchhoff's loop rule

The principle that the sum of the voltage rises and drops around a closed loop in a circuit is equal to zero.

Capacitor

A device that stores charge and energy in an electric field when a voltage is applied.

Capacitance (C)

The ability of a capacitor to store charge per unit voltage, measured in farads (F).

Power (P)

The rate at which electrical energy is converted to another form of energy, calculated as P=IV, where I is current and V is voltage.

Voltage drop

The reduction in voltage across a component in a circuit due to resistance.

Voltage rise

An increase in voltage across a component in a circuit, often caused by a power source.

Potential difference (ΔV)

The difference in electric potential between two points in a circuit, driving the flow of current.

Energy stored in a capacitor

The potential energy stored in a capacitor, given by the formula U=1/2 QΔV, where Q is the charge and ΔV is the voltage across the capacitor.

Internal resistance

A measure of a battery's opposition to the flow of charge, which can cause the voltage across the terminals to be less than the EMF.

Voltage across a resistor

The voltage drop experienced by a resistor in a circuit, calculated using Ohm's law.

Equivalent resistance

The total resistance of a circuit combining multiple resistors, which can be found using different rules for series and parallel configurations.

Microfarad

A unit of capacitance equal to one millionth of a farad.

Nanofarad

A unit of capacitance equal to one billionth of a farad.

Brightness in bulbs

The brightness of a light bulb in a circuit is directly related to the power, which depends on voltage and current.

Inductor

A passive electronic component that stores energy in a magnetic field when electric current flows through it.

Inductance (L)

The property of an inductor that quantifies its ability to store energy in a magnetic field, measured in henries (H).

Dielectric

An insulating material that increases the capacitance of a capacitor when placed between its plates.

Frequency (f)

The number of oscillations or cycles per unit time in an AC circuit, measured in hertz (Hz).

Alternating current (AC)

An electric current that reverses direction periodically, as opposed to direct current (DC), which flows in one direction.

Direct current (DC)

An electric current that flows in one direction only and is typically produced by batteries.

Transformer

A device that transfers electrical energy between two or more circuits through electromagnetic induction.

Magnetic field

A field around a magnet or current-carrying conductor in which magnetic forces can be observed.

Reactance

The opposition to alternating current in a circuit due to capacitors and inductors, measured in ohms.

Impedance (Z)

The total opposition to alternating current, combining resistance and reactance, also measured in ohms.

Resonance

A phenomenon where a system oscillates at greater amplitude at certain frequencies, known as the resonant frequency.

Lenz's Law

The principle stating that the induced current in a closed loop will flow in a direction that opposes the change in magnetic flux.

Transformer efficiency

The ratio of the output power to input power in a transformer, indicating how effectively it converts energy.

Farad (F)

The unit of capacitance, defined as one coulomb per volt.

Coulomb (C)

The SI unit of electric charge, defined as the charge transported by a constant current of one ampere in one second.

Siemens (S)

The unit of electrical conductance, the reciprocal of resistance, equal