Terms starting with V
17 terms
Valence Band
Condensed Matter & Materials Physics
eV (Energy Levels)
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
Van der Pol Oscillator
Waves, Oscillations & Acoustics
N/A
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
Van der Waals Equation
Thermodynamics & Statistical Physics
Pa·m³
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
Variational Principle
Mathematical & Computational Physics
Stationary Action Principle
A fundamental physical principle asserting that true physical trajectories minimize or render stationary a scalar functional (such as action).
δ S = δ ∫_t₁^t₂ L(q, q̇, t) dt = 0 (Hamilton's Principle)
Vector
Foundations of Physics
Various
A physical quantity characterized by both a magnitude and a spatial direction.
A = Ax i + Ay j + Az k
Vector Calculus
Mathematical & Computational Physics
Differential Operators
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)
Vector Components
Foundations of Physics
Various
The scalar projections of a vector along the mutually perpendicular axes of a coordinate system.
Ax = A cos θ, Ay = A sin θ
Vector Product
Foundations of Physics
Various
A vector operation multiplying two 3D vectors to yield a vector perpendicular to both, with magnitude equal to the area of the parallelogram they span.
A × B = |A||B| sin θ n_hat
Velocity
Classical Mechanics
m/s
A vector quantity expressing the time rate of change of position, possessing both speed and direction.
v = dr/dt
Vernier Caliper
Foundations of Physics
mm
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)
Vibration of Strings
Waves, Oscillations & Acoustics
Hz (T in N, μ in kg/m)
Transverse standing wave resonances produced along stretched flexible strings fixed at both ends.
f_n = (n / 2L) √(T / μ), v = √(T / μ)
Virtual Image
Optics
m
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)
Virtual Particles
Nuclear & Particle Physics
Transient Quantum Fluctuation
Transient quantum field fluctuations that mediate interactions between real particles, constrained in lifetime by the energy-time uncertainty principle.
ΔE Δt ≥ ℏ / 2, q² ≠ m² c² (Off mass-shell)
Viscosity
Classical Mechanics
Pa·s (kg/(m·s))
A measure of a fluid's internal resistance to gradual deformation by shear or tensile stress.
τ = η (dv/dy)
Visual Angle
Optics
rad (or arcminutes ')
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)
Vlasov Equation
Plasma Physics
Collisionless Kinetic Operator
The fundamental partial differential equation governing the evolution of the single-particle distribution function f(r, v, t) in a collisionless plasma.
∂f / ∂t + v · ∇_r f + (q / m) (E + v × B) · ∇_v f = 0
Voltage
Electromagnetism & Electronics
V (Volts = J/C)
The electric potential difference between two points, defined as the work required per unit charge to move a positive test charge between them.
V = W / q = I R