176 terms
Capacitance
A region of space where an electric charge experiences a force. Electric field strength E is the force per unit positive
Fields and their consequences
Capacitance
The electric potential energy per unit charge at a point in an electric field, measured in volts (V) or J/C. Potential d
Fields and their consequences
Capacitance
The charge stored per unit potential difference across a conductor or capacitor: C = Q/V, measured in farads (F), where
Fields and their consequences
Capacitance
The electric force per unit positive charge at any point in space. For a point charge Q, the electric field strength at
Fields and their consequences
Capacitance
A device consisting of two parallel conducting plates separated by a small distance, used to store electrical charge and
Fields and their consequences
Capacitance
The process by which a capacitor accumulates or loses electrical charge. During charging through a resistor, Q(t) = Q₀(1
Fields and their consequences
Capacitance
A charged capacitor stores electrical potential energy. Energy stored E = ½QV = ½CV² = Q²/(2C) where Q is charge, V is p
Fields and their consequences
Capacitance
In an RC circuit, the product τ = RC where R is resistance and C is capacitance. Time constant represents the time for c
Fields and their consequences
Circuits
The total energy per unit charge converted from chemical (or other) energy to electrical energy by a source such as a ba
Electricity
Circuits
The resistance within a power source (such as a battery or cell) due to the resistance of the electrolyte and electrodes
Electricity
Circuits
The potential difference measured across the terminals of a power source (battery or cell) in a circuit where current is
Electricity
Circuits
A circuit configuration in which a single voltage source is divided into smaller voltages by arranging resistors in seri
Electricity
Circuits
Kirchhoff's current law (KCL) states that the sum of currents entering a junction equals the sum of currents leaving it.
Electricity
Circuits
Kirchhoff's voltage law (KVL) states that the sum of potential differences around a closed loop in a circuit is zero. Ma
Electricity
Circuits
A potential divider circuit where the load resistance can change (e.g., a thermistor or LDR as the load). The output vol
Electricity
Current electricity
The force exerted by one electric charge on another, determined by Coulomb's law: F = kQ₁Q₂/r². Electric forces are fund
Electricity
Current electricity
The rate of flow of electric charge through a conductor, measured in amperes (A). Defined as I = Q/t, where Q is the cha
Electricity
Current electricity
A fundamental property of matter that determines electrostatic and electromagnetic interactions. Charge is quantised: it
Electricity
Current electricity
The work done per unit charge by an external agent in moving a charge between two points in an electric field, measured
Electricity
Current electricity
A measure of the opposition to current flow in a conductor, measured in ohms (Ω). Defined by Ohm's law: R = V/I, where V
Electricity
Current electricity
An intrinsic material property measuring how strongly a material opposes current flow, measured in ohm-metres (Ω·m). Res
Electricity
Current electricity
For an ohmic conductor at constant temperature, the current is directly proportional to the applied potential difference
Electricity
Current electricity
A graph of current versus potential difference for a component, showing how current responds to applied voltage. Differe
Electricity
Current electricity
A conductor obeying Ohm's law, with resistance independent of applied potential difference and current. Its I-V characte
Electricity
Current electricity
A light source consisting of a thin wire (filament) that glows when heated by electric current. The filament's resistanc
Electricity
Current electricity
A semiconductor component with two terminals (anode and cathode) that conducts current preferentially in one direction.
Electricity
Current electricity
A resistor whose resistance depends strongly on temperature. Negative temperature coefficient (NTC) thermistors decrease
Electricity
Current electricity
A light-dependent resistor (LDR) or photoresistor whose resistance decreases when exposed to light. LDRs are semiconduct
Electricity
Current electricity
A phenomenon in which certain materials at temperatures below their critical temperature show exactly zero electrical re
Electricity
Current electricity
A particle responsible for carrying electric current through a material. In metals, charge carriers are electrons (negat
Electricity
Current electricity
The average velocity at which charge carriers move through a conductor in response to an applied electric field. Despite
Electricity
Electromagnetic radiation and quantum phenomena
The phenomenon in which electrons are emitted from a material when light of sufficiently high frequency shines on it. Th
Particles and radiation
Electromagnetic radiation and quantum phenomena
A discrete packet of electromagnetic radiation carrying energy proportional to its frequency: E = hf, where h is Planck'
Particles and radiation
Electromagnetic radiation and quantum phenomena
The minimum energy required to remove an electron from the surface of a material. Represented by Φ (in joules or eV), th
Particles and radiation
Electromagnetic radiation and quantum phenomena
A discrete energy state available to an electron in an atom. Electrons occupy the lowest available energy levels (ground
Particles and radiation
Electromagnetic radiation and quantum phenomena
The concept that matter and electromagnetic radiation exhibit both wave and particle properties depending on how they ar
Particles and radiation
Electromagnetic radiation and quantum phenomena
Virtual particles that mediate fundamental forces between matter particles. In quantum field theory, forces are transmit
Particles and radiation
Electromagnetic radiation and quantum phenomena
A virtual photon is an ephemeral force-carrying particle (exchange particle) that transmits the electromagnetic force be
Particles and radiation
Electromagnetic radiation and quantum phenomena
A massive elementary particle (mass ~80 GeV/c²) that mediates the weak nuclear force. W bosons come in two varieties: W⁺
Particles and radiation
Electromagnetic radiation and quantum phenomena
A massive, electrically neutral elementary particle (mass ~91 GeV/c²) that mediates neutral-current weak interactions. T
Particles and radiation
Electromagnetic radiation and quantum phenomena
The massless exchange particle that mediates the strong nuclear force between quarks and gluons. Gluons carry colour cha
Particles and radiation
Electromagnetic radiation and quantum phenomena
A pictorial representation of particle interactions developed by Richard Feynman. Time progresses upward (or leftward),
Particles and radiation
Electromagnetic radiation and quantum phenomena
Pair production is the creation of a particle-antiparticle pair (typically electron-positron) from a high-energy photon
Particles and radiation
Electromagnetic radiation and quantum phenomena
A quantum mechanical description of light as discrete packets of energy called photons, each with energy E = hf = hc/λ a
Particles and radiation
Electromagnetic radiation and quantum phenomena
The minimum frequency of light required to eject an electron from a material in the photoelectric effect. It is related
Particles and radiation
Electromagnetic radiation and quantum phenomena
The retarding potential difference required to reduce the kinetic energy of the most energetic photoelectrons to zero, p
Particles and radiation
Electromagnetic radiation and quantum phenomena
The wavelength associated with a moving particle, given by λ = h/p where h is Planck's constant and p is the particle's
Particles and radiation
Energy from the nucleus
The energy required to completely separate a nucleus into individual protons and neutrons. Equivalently, the energy rele
Nuclear physics
Energy from the nucleus
The difference between the total mass of separated nucleons and the actual mass of a nucleus: Δm = [Z × m_p + (A−Z) × m_
Nuclear physics
Energy from the nucleus
The splitting of a heavy nucleus into two smaller fragments (typically near mass numbers around 90 and 140 for uranium-2
Nuclear physics
Energy from the nucleus
The combination of two light nuclei into a heavier nucleus, releasing energy because the product has higher binding ener
Nuclear physics
Energy from the nucleus
The principle that mass and energy are interchangeable, expressed by Einstein's equation E = mc², where E is energy, m i
Nuclear physics
Energy from the nucleus
The binding energy of a nucleus divided by the number of nucleons (A). This quantity varies with A in a characteristic c
Nuclear physics
Energy from the nucleus
A self-sustaining process where neutrons released in one fission event trigger further fissions. If the average number o
Nuclear physics
Energy from the nucleus
The minimum mass of fissile material (e.g., U-235 or Pu-239) required to sustain a chain reaction at multiplication fact
Nuclear physics
Energy from the nucleus
A material in a nuclear reactor that slows down (moderates) neutrons without absorbing them significantly, increasing th
Nuclear physics
Energy from the nucleus
Rods of neutron-absorbing material (typically cadmium or boron) inserted into a reactor core to control the multiplicati
Nuclear physics
Energy from the nucleus
A fluid that removes heat generated by nuclear fission in a reactor core, cooling the reactor and transferring heat to s
Nuclear physics
Fields
A region of space where a massive object exerts a gravitational force on any other mass. Gravitational field strength g
Fields and their consequences
Fields
The gravitational force between two point masses is proportional to their product and inversely proportional to the squa
Fields and their consequences
Fields
The gravitational potential energy per unit mass at a point in a gravitational field, measured in J/kg or m²/s². Denoted
Fields and their consequences
Fields
The gravitational force per unit mass exerted by a massive object on a test mass. At distance r from a point mass M, gra
Fields and their consequences
Fields
The minimum speed an object needs to escape from the gravitational field of a massive body to infinity. Escape velocity
Fields and their consequences
Fields
An orbit around Earth where a satellite's orbital period equals Earth's rotational period (24 hours), so the satellite a
Fields and their consequences
Fields
Three empirical laws describing planetary orbits: (1) Planets move in elliptical orbits with the Sun at one focus. (2) A
Fields and their consequences
Fields
The energy stored in the gravitational field due to the separation of masses. For two point masses M and m separated by
Fields and their consequences
Force, energy and momentum
The change in position of an object, measured as the straight-line distance and direction from the initial to the final
Mechanics and materials
Force, energy and momentum
The rate of change of displacement with time, calculated as v = Δs/Δt (where s is displacement and t is time). A vector
Mechanics and materials
Force, energy and momentum
The rate of change of velocity with time, calculated as a = Δv/Δt (where v is velocity and t is time). A vector quantity
Mechanics and materials
Force, energy and momentum
A push or pull that changes (or tends to change) an object's state of motion, measured in newtons (N). A vector quantity
Mechanics and materials
Force, energy and momentum
The product of mass and velocity: p = mv, measured in kg·m·s⁻¹. A vector quantity (has direction). The rate of change of
Mechanics and materials
Force, energy and momentum
The capacity to do work. Mechanical energy has two forms: kinetic energy (KE = ½mv², energy of motion) and potential ene
Mechanics and materials
Force, energy and momentum
The energy transferred when a force acts over a distance: W = F·s·cos(θ), where F is force, s is displacement, and θ is
Mechanics and materials
Force, energy and momentum
The rate at which work is done or energy is transferred, calculated as P = W/t or P = E/t, measured in watts (W), where
Mechanics and materials
Force, energy and momentum
The process of splitting a vector into two perpendicular components, typically horizontal (x) and vertical (y). If a vec
Mechanics and materials
Force, energy and momentum
A diagram that represents an object and all the forces acting on it. Each force is drawn as an arrow (vector) showing it
Mechanics and materials
Force, energy and momentum
The constant speed reached by an object moving through a fluid when the net force becomes zero, typically when air resis
Mechanics and materials
Force, energy and momentum
The distance a vehicle travels from the moment the brakes are applied until it comes to a complete stop. It depends on t
Mechanics and materials
Force, energy and momentum
The product of force and the time over which it acts: J = FΔt. Impulse equals the change in momentum: J = Δp = m(v - u).
Mechanics and materials
Force, energy and momentum
A collision in which kinetic energy is conserved (in addition to momentum). Both momentum and kinetic energy are conserv
Mechanics and materials
Force, energy and momentum
A collision in which kinetic energy is not conserved (though momentum is always conserved). Some kinetic energy is conve
Mechanics and materials
Limitation of physical measurements
The range of possible values around a measured quantity within which the true value is likely to lie, arising from limit
Measurements and their errors
Limitation of physical measurements
A measure of how large a measurement uncertainty is relative to the measured value, expressed as a percentage. Calculate
Measurements and their errors
Limitation of physical measurements
The meaningful digits in a measurement or calculated result, reflecting the precision of the measurement or appropriate
Measurements and their errors
Limitation of physical measurements
Unpredictable, non-directional variations in measurements caused by uncontrollable factors such as environmental fluctua
Measurements and their errors
Limitation of physical measurements
A consistent, directional error that shifts all measurements in the same direction (higher or lower than the true value)
Measurements and their errors
Limitation of physical measurements
A measure of how close a measured value is to the true or accepted value of a physical quantity. Accuracy reflects the d
Measurements and their errors
Limitation of physical measurements
A measure of how consistently a measurement can be made or how finely a measurement is resolved. High precision means re
Measurements and their errors
Limitation of physical measurements
The smallest difference in value that a measuring instrument can reliably distinguish. It is typically taken as half the
Measurements and their errors
Limitation of physical measurements
The uncertainty in a measurement expressed as an absolute quantity in the same units as the measurement (e.g., ±0.5 m, ±
Measurements and their errors
Limitation of physical measurements
The uncertainty in the gradient (or slope) of a graph, determined by drawing maximum and minimum gradient lines (lines o
Measurements and their errors
Magnetic fields
A region of space where a magnetic force is exerted on a moving charge or current-carrying conductor. Magnetic field str
Fields and their consequences
Magnetic fields
The generation of an electrical current or EMF when magnetic flux through a circuit changes. Faraday's law: EMF = −N(ΔΦ_
Fields and their consequences
Magnetic fields
A measure of the strength of a magnetic field, denoted B and measured in tesla (T). Magnetic flux Φ = B·A·cos(θ) where A
Fields and their consequences
Magnetic fields
A charged particle moving through a magnetic field experiences a magnetic force perpendicular to both velocity and field
Fields and their consequences
Magnetic fields
A device using crossed electric and magnetic fields to select particles with a specific velocity. For particles moving p
Fields and their consequences
Magnetic fields
A particle accelerator using a perpendicular magnetic field to accelerate charged particles in a spiral path. Particles
Fields and their consequences
Magnetic fields
The quantitative law of electromagnetic induction: EMF = -N × dΦ/dt where N is the number of turns in the coil and dΦ/dt
Fields and their consequences
Magnetic fields
The induced current (or induced magnetic field) opposes the change in magnetic flux that causes it. Mathematically, this
Fields and their consequences
Magnetic fields
A device that converts mechanical energy into alternating current (AC) electrical energy. A coil rotates in a uniform ma
Fields and their consequences
Magnetic fields
A device using electromagnetic induction to change AC voltage and current. For an ideal transformer with primary turns N
Fields and their consequences
Materials
A measure of the stiffness of a material, defined as E = stress / strain = (F/A) / (Δx/x), where F is force, A is cross-
Mechanics and materials
Materials
The force per unit area acting on a material: σ = F/A, measured in pascals (Pa). A measure of internal forces within a m
Mechanics and materials
Materials
The fractional change in dimension due to applied stress: ε = Δx/x, where Δx is change in length and x is original lengt
Mechanics and materials
Materials
A graph of stress (force per unit area) on the y-axis versus strain (proportional change in length) on the x-axis, showi
Mechanics and materials
Materials
A material property describing a substance's ability to undergo large plastic (permanent) deformations without breaking.
Mechanics and materials
Materials
A material property indicating a substance's tendency to break (fracture) suddenly with little or no plastic deformation
Mechanics and materials
Materials
Materials composed of long-chain molecules (polymers) with repeating structural units. Polymers can be natural (rubber,
Mechanics and materials
Materials
The energy stored in a material when elastically deformed. For a material under stress, elastic strain energy per unit v
Mechanics and materials
Materials
The maximum stress a material can withstand before breaking (fracture). It is found on a stress-strain graph as the stre
Mechanics and materials
Materials
A fundamental principle stating that the extension (or compression) of a spring or elastic material is proportional to t
Mechanics and materials
Materials
An arrangement where springs are connected end-to-end so the same force acts on each. For springs in series, the recipro
Mechanics and materials
Materials
An arrangement where springs are attached to the same two points so the applied force is distributed among them. For spr
Mechanics and materials
Particles
An atom consists of a nucleus (protons and neutrons) surrounded by an electron cloud. Protons and neutrons together form
Particles and radiation
Particles
The number of protons in the nucleus of an atom, denoted by Z. Atomic number uniquely identifies the chemical element; a
Particles and radiation
Particles
The total number of protons and neutrons in the nucleus of an atom, denoted by A. Mass number does not include electrons
Particles and radiation
Particles
Atoms of the same element (same atomic number Z) that have different numbers of neutrons and therefore different mass nu
Particles and radiation
Particles
A nucleus that does not undergo radioactive decay and remains unchanged over time. Stability depends on the balance betw
Particles and radiation
Particles
A nucleus with too many or too few neutrons relative to the number of protons, causing it to decay radioactively in an a
Particles and radiation
Particles
The force between two point charges is proportional to the product of the charges and inversely proportional to the squa
Particles and radiation
Particles
A standardised system for representing subatomic particles using symbols and quantum numbers. Notation includes the part
Particles and radiation
Particles
A type of radioactive decay in which a proton is converted into a neutron, a positron (β⁺, the antimatter counterpart of
Particles and radiation
Particles
A rare decay process in which a nucleus captures one of its own atomic electrons (usually from the K-shell closest to th
Particles and radiation
Particles
An electrically neutral, weakly interacting elementary particle with nearly zero rest mass. Neutrinos are produced in be
Particles and radiation
Particles
A quantum number conserved in all interactions, defined as +1 for baryons (protons, neutrons), -1 for antibaryons, and 0
Particles and radiation
Particles
A conserved quantum number assigned to leptons and their interactions. Electrons and electron neutrinos have lepton numb
Particles and radiation
Particles
A quantum number assigned to particles containing strange quarks. Strangeness is conserved in strong nuclear interaction
Particles and radiation
Periodic motion
Motion of an object in a circular path at constant speed. Although speed is constant, velocity is not (direction changes
Further mechanics and thermal physics
Periodic motion
The acceleration directed toward the centre of a circular path, responsible for continuously changing the direction of v
Further mechanics and thermal physics
Periodic motion
The resultant force directed toward the centre of a circular path, necessary to cause centripetal acceleration and maint
Further mechanics and thermal physics
Periodic motion
The rate of change of angular position, measured in radians per second (rad·s⁻¹). Denoted ω, it relates to linear veloci
Further mechanics and thermal physics
Periodic motion
Oscillatory motion in which the acceleration is directly proportional to displacement but opposite in direction: a = −ω²
Further mechanics and thermal physics
Periodic motion
The maximum displacement of an oscillating object from its equilibrium position, measured in metres. Denoted by A, ampli
Further mechanics and thermal physics
Periodic motion
Oscillations of a system driven by an external periodic force at a frequency f_drive. If the driving frequency matches t
Further mechanics and thermal physics
Periodic motion
The phenomenon in which a system oscillates with maximum amplitude when driven at its natural frequency. At resonance, t
Further mechanics and thermal physics
Periodic motion
The dissipation of mechanical energy from an oscillating system through friction, air resistance, or other resistive for
Further mechanics and thermal physics
Periodic motion
Curves on roads or tracks tilted at an angle to the horizontal, so the normal force has a component pointing toward the
Further mechanics and thermal physics
Periodic motion
A pendulum bob moving in a horizontal circle at constant radius, with the string making a constant angle to the vertical
Further mechanics and thermal physics
Periodic motion
In simple harmonic motion, the total mechanical energy remains constant, oscillating between kinetic and potential energ
Further mechanics and thermal physics
Progressive and stationary waves
A wave that travels through space, transferring energy from one location to another. Particles oscillate about equilibri
Waves
Progressive and stationary waves
The distance between consecutive points in phase (e.g., between adjacent crests or troughs) in a progressive wave, measu
Waves
Progressive and stationary waves
The number of complete oscillations (or wave cycles) per unit time, measured in hertz (Hz), where 1 Hz = 1 cycle per sec
Waves
Progressive and stationary waves
A wave in which particles oscillate perpendicular to the direction of energy transfer. Examples include electromagnetic
Waves
Progressive and stationary waves
A wave in which particles oscillate parallel to the direction of energy transfer, alternating between compression and ra
Waves
Progressive and stationary waves
A wave pattern formed by the superposition of two progressive waves of equal frequency and amplitude travelling in oppos
Waves
Radioactivity
The spontaneous emission of radiation (alpha, beta, or gamma) by unstable nuclei as they decay toward stability. Radioac
Nuclear physics
Radioactivity
The radioactive decay of an unstable nucleus by emitting an alpha particle (helium-4 nucleus: ⁴He or ⁴₂He), reducing the
Nuclear physics
Radioactivity
The radioactive decay of an unstable nucleus by emitting a beta particle (electron: ⁰₋₁ e or ⁰₋₁ β) and an antineutrino.
Nuclear physics
Radioactivity
The radioactive decay of an excited nucleus by emitting a high-energy photon (gamma ray: γ) without changing the number
Nuclear physics
Radioactivity
The deflection of alpha particles (helium-4 nuclei) by atomic nuclei, studied experimentally by Rutherford. Rutherford s
Nuclear physics
Radioactivity
The average density of matter within an atomic nucleus, approximately ρ ≈ 2.3 × 10¹⁷ kg/m³. Nuclear density is essential
Nuclear physics
Refraction, diffraction and interference
The phenomenon where two or more waves superpose, resulting in a combined wave pattern. Constructive interference occurs
Waves
Refraction, diffraction and interference
The bending of waves around obstacles or through apertures when the wavelength is comparable to the obstacle/aperture si
Waves
Refraction, diffraction and interference
The bending of a wave when it crosses a boundary between media with different wave speeds. Snell's law: n₁ sin(θ₁) = n₂
Waves
Thermal physics
A measure of the average kinetic energy of particles in a substance, indicating how hot or cold the substance is. Temper
Further mechanics and thermal physics
Thermal physics
The transfer of thermal energy from a hotter region to a colder region due to a temperature difference. Heat is measured
Further mechanics and thermal physics
Thermal physics
The energy required to raise the temperature of 1 kg of a substance by 1 K, measured in J/(kg·K). Denoted by c, it is a
Further mechanics and thermal physics
Thermal physics
The energy required to change the state of a substance (solid ↔ liquid ↔ gas) at constant temperature. Denoted by L, lat
Further mechanics and thermal physics
Thermal physics
The total kinetic and potential energy of all particles in a substance, related to temperature and state (solid, liquid,
Further mechanics and thermal physics
Thermal physics
A theoretical gas obeying the ideal gas equation pV = nRT, where p is pressure, V is volume, n is number of moles, R = 8
Further mechanics and thermal physics
Thermal physics
The molecular theory explaining gas behaviour as arising from random particle motion. Kinetic theory predicts that press
Further mechanics and thermal physics
Thermal physics
The energy per unit mass required to change a substance's physical state at constant temperature and pressure. Specific
Further mechanics and thermal physics
Thermal physics
A method for measuring specific heat capacity or latent heat by passing a fluid (liquid or gas) continuously through a h
Further mechanics and thermal physics
Thermal physics
An ideal gas law stating that at constant temperature, pressure is inversely proportional to volume: PV = constant, or P
Further mechanics and thermal physics
Thermal physics
An ideal gas law stating that at constant pressure, volume is directly proportional to absolute temperature: V/T = const
Further mechanics and thermal physics
Thermal physics
An ideal gas law stating that at constant volume, pressure is directly proportional to absolute temperature: P/T = const
Further mechanics and thermal physics
Thermal physics
The number of atoms or molecules in one mole of a substance: N_A = 6.02 × 10²³ mol⁻¹. It is a fundamental constant linki
Further mechanics and thermal physics
Thermal physics
A fundamental constant k_B = 1.38 × 10⁻²³ J/K relating the energy scale of individual particles to temperature. It appea
Further mechanics and thermal physics
Thermal physics
The square root of the average of the squared speeds of gas particles: v_rms = √(3k_B T/m) = √(3RT/M) where T is absolut
Further mechanics and thermal physics
Use of SI units and their prefixes
One of seven fundamental units of measurement in the International System of Units that cannot be derived from other uni
Measurements and their errors
Use of SI units and their prefixes
A standardised multiplier applied to SI units to express values over a wide range of magnitudes. Common prefixes include
Measurements and their errors
Use of SI units and their prefixes
A unit of measurement that is created by combining two or more SI base units through multiplication or division. Example
Measurements and their errors
Use of SI units and their prefixes
A physical quantity that has no units and is determined by a numerical value alone. Examples include refractive index, r
Measurements and their errors
Use of SI units and their prefixes
The process of expressing a measured quantity in different units while preserving the actual value. Conversion requires
Measurements and their errors
Use of SI units and their prefixes
A method of checking the consistency of equations and converting between units by tracking how dimensions (base units) c
Measurements and their errors
Use of SI units and their prefixes
A rough estimate of the size of a physical quantity expressed as a power of 10. Orders of magnitude allow physicists to
Measurements and their errors