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842 terms · page 34 of 36


A–Z
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Foundations of Physics

Unit Vector

A dimensionless vector with a magnitude of exactly one, used exclusively to specify a direction in space.

û = u / |u| Dimensionless
Plasma Physics

Upper & Lower Hybrid Resonances

Characteristic wave resonance frequencies in magnetized plasmas where wave group velocity vanishes and electromagnetic energy couples…

Upper: ω_UH = √(ω_pe² + ω_ce²); Lower: 1 / ω_LH² = 1 / (ω_ci² + ω_pi²) + 1 / (ω_ce ω_ci) rad/s (Resonance Frequencies)
Condensed Matter & Materials Physics

Valence Band

The highest range of electron energy bands in a solid that is fully occupied by bound valence electrons at absolute zero temperature.

Occupied by valence electrons at T = 0 K eV (Energy Levels)
Waves, Oscillations & Acoustics

Van der Pol Oscillator

A non-linear oscillator with non-linear damping that exhibits stable self-sustained limit cycle vibrations.

d²x/dt² - μ (1 - x²) dx/dt + x = 0 N/A
Thermodynamics & Statistical Physics

Van der Waals Equation

An equation of state modifying the ideal gas law to account for finite molecular volume and attractive intermolecular forces in real gases.

(P + a n² / V²) (V - n b) = n R T Pa·m³
Mathematical & Computational Physics

Variational Principle

A fundamental physical principle asserting that true physical trajectories minimize or render stationary a scalar functional (such as…

δ S = δ ∫_t₁^t₂ L(q, q̇, t) dt = 0 (Hamilton's Principle) Stationary Action Principle
Foundations of Physics

Vector

A physical quantity characterized by both a magnitude and a spatial direction.

A = Ax i + Ay j + Az k Various
Mathematical & Computational Physics

Vector Calculus

A branch of mathematics dealing with multivariable differentiation and integration of vector fields in 3D Euclidean space.

∇f (Grad), ∇ · F (Div), ∇ × F (Curl), ∇²f (Laplacian) Differential Operators
Foundations of Physics

Vector Components

The scalar projections of a vector along the mutually perpendicular axes of a coordinate system.

Ax = A cos θ, Ay = A sin θ Various
Foundations of Physics

Vector Product

A vector operation multiplying two 3D vectors to yield a vector perpendicular to both, with magnitude equal to the area of the…

A × B = |A||B| sin θ n_hat Various
Classical Mechanics

Velocity

A vector quantity expressing the time rate of change of position, possessing both speed and direction.

v = dr/dt m/s
Foundations of Physics

Vernier Caliper

A precision measuring instrument utilizing a main scale and a sliding Vernier scale to measure linear dimensions with fine precision.

Reading = Main Scale + (Vernier Coincidence × Least Count) mm
Waves, Oscillations & Acoustics

Vibration of Strings

Transverse standing wave resonances produced along stretched flexible strings fixed at both ends.

f_n = (n / 2L) √(T / μ), v = √(T / μ) Hz (T in N, μ in kg/m)
Optics

Virtual Image

An optical image formed where light rays appear to diverge from, but do not actually intersect; cannot be projected on a screen.

v < 0 (for virtual image), m > 0 (upright) m
Nuclear & Particle Physics

Virtual Particles

Transient quantum field fluctuations that mediate interactions between real particles, constrained in lifetime by the energy-time…

ΔE Δt ≥ ℏ / 2, q² ≠ m² c² (Off mass-shell) Transient Quantum Fluctuation
Classical Mechanics

Viscosity

A measure of a fluid's internal resistance to gradual deformation by shear or tensile stress.

τ = η (dv/dy) Pa·s (kg/(m·s))
Optics

Visual Angle

The angle subtended at the eye's nodal point by an object, determining the size of the image formed on the retina.

θ ≈ h / d (in radians for small angles) rad (or arcminutes ')
Plasma Physics

Vlasov Equation

The fundamental partial differential equation governing the evolution of the single-particle distribution function f(r, v, t) in a…

∂f / ∂t + v · ∇_r f + (q / m) (E + v × B) · ∇_v f = 0 Collisionless Kinetic Operator
Electromagnetism & Electronics

Voltage

The electric potential difference between two points, defined as the work required per unit charge to move a positive test charge between…

V = W / q = I R V (Volts = J/C)
Nuclear & Particle Physics

W and Z Bosons

Massive elementary vector gauge bosons that mediate the weak nuclear interaction.

M_W ≈ 80.38 GeV/c², M_Z ≈ 91.19 GeV/c², Spin = 1 GeV/c² (Rest Mass Energy)
Geophysics & Environmental Physics

Wadati-Benioff Zone

A planar dipping zone of earthquake foci produced by the subduction of a cold, rigid oceanic lithospheric plate into the mantle.

Seismic Focal Depth down to ~670 km along dipping slab km (Focal Depth)
Thermodynamics & Statistical Physics

Water Equivalent

The mass of water that absorbs or releases the exact same amount of heat as a calorimeter body for an identical temperature change.

w = m_cal c_cal / c_water kg (or g)
Electromagnetism & Electronics

Wattless Current

The component of alternating current that is 90 degrees out of phase with AC voltage, consuming zero net electrical power.

I_wattless = I_rms sin φ A (Amperes)
Waves, Oscillations & Acoustics

Wave Dispersion

The phenomenon where wave phase velocity depends on wave frequency or wavelength in a medium.

v_p = f(λ), d²ω/dk² ≠ 0 N/A