Physics Terminology: Essential Physics Terminology Part-4. 200 Terms (from P to S)

Physics Terminology: Essential Physics Terminology Part-4

Physics Terminology

Physics terminology refers to the specialised words and expressions used to describe physical concepts, phenomena, measurements, processes, and laws. These terms provide a precise and standardised language that scientists, students, engineers and researchers use to communicate ideas clearly and accurately.

Because physics deals with the fundamental behaviour of matter, energy, space and time, its vocabulary needs to be exact. Terms such as force, momentum, entropy, frequency, wavelength, resistance, and quantum state each carry specific scientific meanings that differ from their everyday usage. Misunderstanding or misusing these terms can lead to incorrect conclusions or confusion.

Physics terminology is often derived from Latin, Greek, or the names of scientists who made significant contributions-for example, joule, newton, tesla, and curie. Many terms are also linked to mathematical representations, units of measurement or experimental observations.

A good grasp of physics terms helps in:

• Understanding textbooks, lectures and scientific papers
• Solving numerical and conceptual problems
• Describing experiments and results accurately
• Connecting theories with real-world applications
• Communicating clearly in academic, research or technical settings

Overall, physics terminology forms the foundation of effective learning and communication in the subject. Developing familiarity with these terms enables better comprehension of concepts and strengthens one’s ability to apply physics in practical and advanced contexts.

Physics Terminology: 200 Terms (from P to S)

Here are 200 terms (from P to S)

Physics Terminology (P)

• Pascal (Pa)– The SI unit of pressure, equal to one newton per square metre.
• Pascal’s Law– States that pressure applied to a confined fluid is transmitted equally in all directions.
• Pauli Exclusion Principle– States that no two fermions can occupy the same quantum state simultaneously.
• Pendulum– A mass suspended from a pivot, swinging under the influence of gravity.
• Periodic Motion– Motion that repeats itself at regular intervals of time.
• Periodic Table– A table of chemical elements organised by atomic number and properties.
• Periodic Wave– A wave that repeats its shape at regular intervals in space or time.
• Permeability– A measure of how easily a material can support the formation of a magnetic field within itself.
• Photon– A particle representing a quantum of light or electromagnetic radiation.
• Photoelectric Effect– The emission of electrons from a material when it absorbs light.
• Photodiode– A semiconductor device that converts light into electrical current.
• Photomultiplier Tube– A device that amplifies weak light signals into measurable electrical currents.
• Photonics– The science of generating, controlling, and detecting photons.
• Physical Constant– A universal quantity, such as the speed of light, that does not change.
• Physical Quantity– A property of a system that can be measured, such as mass, length, or time.
• Piezometer– An instrument for measuring fluid pressure.
• Piezoresistive Effect– The change in electrical resistance of a material due to applied mechanical stress.
• Piezoelectric Effect– The generation of electric charge in certain materials when mechanically stressed.
• Pilot Wave– A concept in quantum mechanics suggesting particles are guided by a wave.
• Planck Constant (h)– A fundamental constant used in quantum mechanics, relating energy and frequency.
• Planck Length– The smallest meaningful length scale in physics, based on quantum gravity.
• Planck Time– The smallest meaningful time interval in physics.
• Planck’s Law– Describes the spectral density of radiation emitted by a black body.
• Plasma– A state of matter consisting of free electrons and ions.
• Plasma Frequency– The natural oscillation frequency of electrons in a plasma.
• Plasma Physics– The study of ionised gases and their interactions with electric and magnetic fields.
• Polarisation– The orientation of the oscillations of a transverse wave, especially light.
• Polarimeter– An instrument for measuring the angle of rotation caused by polarised light.
• Polar Molecule– A molecule with an uneven distribution of charge.
• Polar Orbit– An orbit passing over the Earth’s poles, used by some satellites.
• Potential Difference (Voltage)– The work done per unit charge to move a charge between two points.
• Potential Energy– Energy possessed by an object due to its position or configuration.
• Power– The rate at which work is done or energy is transferred, measured in watts.
• Pressure– Force exerted per unit area.
• Projectile Motion– The motion of an object under the influence of gravity along a curved path.
• Proportionality Constant– A constant relating two quantities in a physical law.
• Proton– A positively charged subatomic particle found in atomic nuclei.
• Proton Accelerator– A device that accelerates protons to high speeds for experiments.
• Proton Decay– A hypothetical process in which a proton transforms into lighter subatomic particles.
• Proton Mass– The mass of a proton, approximately 67×10−271.67×10−27 kg.
• Proton Number (Atomic Number)– The number of protons in an atomic nucleus.
• Pulse– A sudden disturbance moving through a medium, transferring energy.
• Pulse Width– The duration of a single pulse in a waveform.
• Pulsar– A rotating neutron star emitting regular pulses of electromagnetic radiation.
• Pump Laser– A laser used to provide energy to another laser medium for population inversion.
• Pure Substance– A material with constant chemical composition and uniform properties.
• Pyrometer– A device to measure high temperatures, often without contact.
• Planar Wave– A wave whose wavefronts are infinite, flat surfaces perpendicular to the direction of propagation.
• Polar Coordinates– A coordinate system using radius and angle to define positions in a plane.
• Paramagnetism– A type of magnetism where materials are weakly attracted to a magnetic field.

Physics Terminology (Q)

• Quantum– The smallest discrete quantity of energy or matter that can be involved in physical processes.
• Quantum Chromodynamics (QCD)– The theory describing the strong interaction between quarks and gluons.
• Quantum Computing– The use of quantum-mechanical phenomena, such as superposition and entanglement, to perform computation.
• Quantum Efficiency– The ratio of the number of events produced to the number of photons or particles incident on a system.
• Quantum Entanglement– A phenomenon where particles remain interconnected so that the state of one instantly affects the other.
• Quantum Field Theory– The theoretical framework combining quantum mechanics and special relativity to describe particle interactions.
• Quantum Gravity– A theoretical field aiming to describe gravity according to the principles of quantum mechanics.
• Quantum Hall Effect– A quantum phenomenon of 2D electron systems in a strong magnetic field showing quantised Hall resistance.
• Quantum Jump– A sudden transition of an electron between energy levels in an atom.
• Quantum Mechanics– The branch of physics studying the behaviour of particles at atomic and subatomic scales.
• Quantum Number– A number that describes values of conserved quantities in quantum systems, such as energy or angular momentum.
• Quantum Optics– The study of light and its interaction with matter at the quantum level.
• Quantum State– The complete description of a particle or system in quantum mechanics.
• Quantum Tunnelling– The phenomenon where a particle passes through a potential barrier that it classically could not surmount.
• Quantum Well– A potential well that confines particles, such as electrons, to discrete energy levels.
• Quantum Wire– A one-dimensional nanostructure allowing electron movement along a single axis.
• Quantum Yield– The efficiency with which absorbed photons produce a desired effect in a system.
• Quark– Fundamental particles that combine to form hadrons, such as protons and neutrons.
• Quasiparticle– An emergent particle-like entity arising from the collective behaviour of many particles.
• Quasi-Elastic Scattering– A type of particle scattering that is nearly elastic but with minor energy loss.
• Quasistatic Process– A process that occurs slowly enough for the system to remain in approximate equilibrium.
• Quench (Superconductivity)– The sudden loss of superconductivity due to exceeding critical temperature, current, or magnetic field.
• Quark-Gluon Plasma– A high-energy state of matter where quarks and gluons are free from hadrons.
• Quantum Dot– A nanoscale semiconductor particle that confines electrons in three dimensions.
• Quantum Fluctuation– Temporary changes in energy levels or fields due to the uncertainty principle.
• Quantum Interference– The phenomenon where quantum probability amplitudes combine to enhance or cancel outcomes.
• Quantum Key Distribution (QKD)– A secure communication method using quantum mechanics principles.
• Quantum Oscillator– A system exhibiting quantised energy levels in oscillatory motion.
• Quantum Phase Transition– A transition between different quantum states at absolute zero temperature.
• Quantum Spin– The intrinsic angular momentum of a particle in quantum mechanics.
• Quantum Superposition– The ability of a quantum system to exist in multiple states simultaneously.
• Quantum Vacuum– The lowest energy state in quantum field theory, not empty but containing fluctuations.
• Quantum Well Laser– A semiconductor laser with an active region that confines carriers in a quantum well.
• Quantum Zeno Effect– The suppression of quantum evolution by frequent observation of the system.
• Quench Cooling– Rapid cooling of a material, often used in metallurgy and superconductivity studies.
• Quadrupole– A system or field with two pairs of equal and opposite charges or magnetic poles.
• Quasilinear System– A system where nonlinear effects are small enough to approximate linear behaviour.
• Quench Protection– Methods to prevent damage in superconducting systems when quenching occurs.
• Quantum Teleportation– The transfer of quantum states from one particle to another over distance.
• Quasiparticle Interference– Patterns arising from the scattering of quasiparticles in a material.
• Quantum Confinement– Restriction of particle motion leading to discrete energy levels.
• Quantum Cascade Laser– A semiconductor laser emitting in the mid- to far-infrared range using electron transitions between quantum wells.
• Quantum Dot Photodetector– A device using quantum dots to detect light efficiently.
• Quantum Key– A cryptographic key derived from quantum processes for secure communication.
• Quark Confinement– The principle that quarks cannot exist in isolation and are always bound in hadrons.
• Quantum Gravity Wave– Hypothetical waves resulting from quantum-level gravitational interactions.
• Quasi-Particle Density– The effective density of quasiparticles in a system.
• Quantum Coherence– The property that allows quantum systems to exhibit interference and superposition.
• Quasi-Elastic Electron Scattering– Electron scattering off nuclei that is nearly elastic.
• Quantum Circuit– A system of quantum bits (qubits) used to perform quantum computation.

Physics Terminology (R)

• Radiation– The emission or transmission of energy in the form of waves or particles.
• Radioactive Decay– The spontaneous transformation of an unstable nucleus into a more stable one, emitting radiation.
• Radioactive Half-Life– The time required for half of a radioactive sample to decay.
• Radioactive Isotope– An isotope that undergoes radioactive decay.
• Radioactive Series– A sequence of radioactive decays leading to a stable nucleus.
• Radiance– The amount of energy emitted, reflected, transmitted, or received per unit area per unit solid angle.
• Radiant Energy– Energy carried by electromagnetic waves.
• Radiant Flux– The total power emitted in the form of radiation, measured in watts.
• Radiometer– An instrument for detecting or measuring radiant energy.
• Radiowave– Electromagnetic waves with long wavelengths used for communication.
• Radius of Curvature– The radius of the circular arc that best fits a curved surface.
• Ray– A line representing the path of light in geometric optics.
• Rayleigh Scattering– Scattering of light by particles much smaller than the wavelength, responsible for the blue sky.
• Rayleigh Wave– A type of surface seismic wave that rolls along the ground.
• Reaction Force– The force exerted in response to an applied force, as per Newton’s third law.
• Reactive Power– The component of alternating current power that does not perform work but sustains the electric and magnetic fields.
• Real Image– An image formed where light rays actually converge and can be projected on a screen.
• Rectifier– An electrical device that converts alternating current to direct current.
• Refractive Index– The ratio of the speed of light in a vacuum to its speed in a medium.
• Refraction– The bending of light when it passes from one medium to another with different optical densities.
• Reflection– The bouncing back of light, sound, or other waves from a surface.
• Refractive Surface– A surface that causes the refraction of light.
• Relative Humidity– The ratio of the current moisture in the air to the maximum it can hold at the same temperature.
• Relative Motion– Motion of an object as observed from a particular frame of reference.
• Relativistic Mass– The mass of a particle increasing with its velocity according to relativity.
• Relativistic Mechanics– Mechanics considering effects of special relativity at high velocities.
• Relativistic Momentum– Momentum of a particle accounting for relativistic effects.
• Relativistic Time Dilation– Slowing down of time for a moving observer relative to a stationary one.
• Resistance– Opposition offered by a material to the flow of electric current.
• Resistivity– A material property indicating how strongly it opposes current flow.
• Resonance– Maximum response of a system when subjected to a frequency matching its natural frequency.
• Resonant Frequency– The frequency at which a system naturally oscillates with maximum amplitude.
• Rest Energy– The energy inherent in a particle at rest, given by E=mc2E=mc2.
• Rest Mass– The intrinsic mass of a particle when it is at rest.
• Resultant Force– A single force producing the same effect as multiple forces acting together.
• Reverse Bias– A condition in which a p-n junction prevents current flow.
• Rheostat– A variable resistor used to control current.
• Rigid Body– An idealised object that does not deform under force.
• Riemann Surface– A mathematical concept used in complex analysis and quantum mechanics.
• RMS (Root Mean Square)– A statistical measure of the magnitude of a varying quantity, such as current or voltage.
• Rocket– A vehicle that moves by expelling mass in the opposite direction, following Newton’s third law.
• Rocket Equation– The equation describing a rocket’s motion considering changing mass and thrust.
• Rotational Kinematics– The study of rotational motion of objects without considering forces.
• Rotational Motion– Motion around a fixed axis.
• Rotational Inertia– Same as moment of inertia, the resistance of a body to rotational motion.
• Rotational Kinetic Energy– Energy possessed by a rotating body due to its rotation.
• Rutherford Scattering– Scattering of charged particles by atomic nuclei, used to study atomic structure.
• Radio Interferometry– A technique using multiple radio telescopes to achieve higher resolution.
• Radiation Pressure– Pressure exerted upon surfaces due to absorption or reflection of electromagnetic radiation.
• Ray Optics– A branch of optics treating light propagation as rays, useful for reflection and refraction analysis.

Physics Terminology (S)

• Sample– A portion of matter used for observation or measurement in experiments.
• Scalar Quantity– A physical quantity described only by magnitude, such as temperature or mass.
• Scattering– The deflection of particles or waves due to interaction with other particles or obstacles.
• Schrödinger Equation– A fundamental equation in quantum mechanics describing the evolution of a system’s wavefunction.
• Screen– A surface on which images, light patterns, or radiation are projected or observed.
• Second (s)– The SI unit of time, defined by the vibration of cesium atoms.
• Second Law of Thermodynamics– States that the entropy of an isolated system always increases over time.
• Secondary Electron– An electron emitted from a material as a result of incident radiation or particles.
• Semiconductor– A material with electrical conductivity between that of a conductor and an insulator.
• Semimetal– A material with properties between metals and semiconductors.
• Series Circuit– A circuit in which components are connected end-to-end, so current is the same through all.
• Shock Wave– A propagating disturbance in a medium with abrupt changes in pressure, temperature, and density.
• Short Circuit– An unintended low-resistance path in an electrical circuit causing excessive current.
• Shunt– A parallel path in a circuit used to measure or divert current.
• SI Unit– A standard unit of measurement defined by the International System of Units.
• Signal-to-Noise Ratio (SNR)– The ratio of the desired signal power to the background noise power.
• Simple Harmonic Motion (SHM)– Oscillatory motion where restoring force is proportional to displacement.
• Simple Pendulum– A mass suspended by a string or rod, oscillating in SHM under gravity.
• Sine Wave– A smooth, periodic oscillation described by a sine function.
• Sink (Thermodynamics)– A reservoir that absorbs heat or energy without changing its temperature significantly.
• Slit Interference– The pattern of bright and dark fringes formed when waves pass through narrow openings.
• Snell’s Law– The law describing the refraction of light when passing between two media.
• Solenoid– A coil of wire that produces a magnetic field when carrying current.
• Solid State Physics– The study of rigid matter and its properties at atomic and molecular levels.
• Sound– Mechanical vibrations transmitted through a medium perceived by the human ear.
• Sound Intensity– The power per unit area carried by a sound wave.
• Sound Wave– A longitudinal wave caused by the vibration of particles in a medium.
• Specific Heat– The amount of heat required to raise the temperature of a unit mass of a substance by one degree.
• Specific Latent Heat– The heat required to change the phase of a unit mass of a substance without temperature change.
• Spectroscopy– The study of interaction between matter and electromagnetic radiation.
• Spectrum– The range of different wavelengths of electromagnetic radiation.
• Spin (Quantum Mechanics)– The intrinsic angular momentum of a particle.
• Spring Constant– A measure of a spring’s stiffness in Hooke’s Law.
• Spring-Mass System– A system consisting of a mass attached to a spring used to study oscillations.
• Standing Wave– A wave pattern that appears stationary due to interference of two waves traveling in opposite directions.
• Statistical Mechanics– The branch of physics connecting microscopic particle behaviour with macroscopic thermodynamic properties.
• Stefan-Boltzmann Law– States that the total energy radiated per unit surface area of a black body is proportional to the fourth power of its temperature.
• Strain– The deformation per unit length of a material under stress.
• Stress– Force per unit area applied to a material.
• Strontium– An alkaline earth metal used in fireworks, magnets, and some physics experiments.
• Strong Nuclear Force– The force binding protons and neutrons in atomic nuclei.
• Superconductivity– The phenomenon of zero electrical resistance in some materials below a critical temperature.
• Superfluidity– A phase of matter with zero viscosity, allowing flow without energy loss.
• Superposition Principle– States that the resultant of multiple waves is the sum of individual displacements.
• Surface Tension– The elastic tendency of a liquid surface minimizing its area.
• Suspension– A heterogeneous mixture where solid particles are dispersed in a fluid.
• Synchronous Motor– An AC motor that rotates at a speed synchronized with supply frequency.
• Synchrotron– A particle accelerator in which charged particles are accelerated along a circular path using magnetic fields.
• System (Physics)– A defined portion of the universe chosen for study, separated by boundaries.
• Sagnac Effect– A phase shift observed in a rotating interferometer, used in ring laser gyroscopes.

 Conclusion

 Physics terminology is not just vocabulary – it is the backbone of understanding and communicating scientific ideas with clarity and precision. Each term represents a well-defined concept, law, measurement, or phenomenon, helping to eliminate ambiguity and foster accurate interpretation across education, research, and application.

From classical mechanics and thermodynamics to quantum theory and astrophysics, mastery of terminology allows learners and professionals to:

• Grasp complex ideas more easily
• Connect theory with real-world observations
• Interpret scientific data correctly
• Communicate findings with consistency and confidence
• Build a strong foundation for advanced study or research

In essence, physics terminology serves as the universal language of the physical sciences. Whether used in classrooms, laboratories, engineering fields, or space research, these terms empower individuals to explore, explain and expand our understanding of the universe.

Go to Essential Physics Terminology Part-1 ( A to E)

Go to Essential Physics Terminology Part-2 (F to I)

Go to Essential Physics Terminology Part-3 (J to O)

Go to Essential Physics Terminology Part-5 (T to Z)

Go to Home Page

Check out www.techmindspro.com for Technology and Engineering related posts