Physics Exam 2: Concepts by Unit (Optics, Electricity, and Modern Physics)

Comprehensive vocabulary flashcards covering light properties, ray optics, optical sign conventions, electric forces, fields, and potentials for Exam 2 preparation.

Wave-Particle Duality

The principle that entities such as light and electrons exhibit both wave-like and particle-like properties depending on the experimental interaction.

De Broglie Wavelength

The wavelength associated with a particle, given by $\lambda = \frac{h}{p}$, which relates momentum to wave properties for both photons and massive particles.

Wavefunction Amplitude Squared ($|\psi|^2$)

A quantity proportional to probability density, used to determine and compare the relative probabilities of finding a particle in space.

Standing Waves in a Box

Confined wave modes satisfying $\frac{n\lambda}{2} = L$ with quantized, positive energy levels given by $E_n = \frac{h^2 n^2}{8mL^2}$, depending on quantum number $n$, mass $m$, and box length $L$.

Hydrogen Energy Levels

The quantized, negative bound-state energies of an electron in a hydrogen atom, calculated using $E_n = -\frac{Rhc}{n^2}$.

Law of Reflection

The relationship $\theta_i = \theta_r$, where the angle of incidence equals the angle of reflection, with both angles measured from the surface normal.

Law of Refraction (Snell's Law)

The relationship $n_1 \sin(\theta_1) = n_2 \sin(\theta_2)$ describing the bending of light across an interface between two media of differing refractive indices.

Refractive Index ($n$)

The ratio of the speed of light in vacuum to the speed of light in a medium ($n = \frac{c}{v}$); a higher index corresponds to a slower light speed and a shorter wavelength.

Optical Element

A light-redirecting device, specifically a lens or a mirror.

Image

An apparent reproduction of an object formed by reflection and/or refraction through one or more optical elements.

Erect Image

An image that shares the same upright orientation as the original object, corresponding to a positive magnification ($m > 0$).

Inverted Image

An image that is upside-down relative to the original object, corresponding to a negative magnification ($m < 0$).

Optical Axis

The central reference line perpendicular to the optical element at its vertex.

Vertex

The specific point where the optical axis intersects the surface of the optical element.

Lens Center

The central point of a lens where a converging lens is at its thickest or a diverging lens is at its thinnest.

Mirror Center of Curvature

The center of the sphere of which a spherical mirror's reflective surface forms a segment.

Real Object

An object positioned on the incoming-light side of an optical element, designated by a positive object distance ($o > 0$).

Virtual Object

An object positioned on the side opposite the incoming light, designated by a negative object distance ($o < 0$).

Real Image

An image formed on the outgoing-light side where actual light rays intersect, corresponding to a positive image distance ($i > 0$).

Virtual Image

An image formed where backward extensions of outgoing rays intersect on the side opposite outgoing light, corresponding to a negative image distance ($i < 0$).

Converging Element

An optical device, such as a convex lens or a concave mirror, that focuses light and has a positive focal length ($f > 0$).

Diverging Element

An optical device, such as a concave lens or a convex mirror, that spreads light rays apart and has a negative focal length ($f < 0$).

Magnification ($m$)

The ratio given by $m = \frac{h_i}{h_o} = -\frac{i}{o}$, where the sign indicates orientation and the absolute value determines relative image size.

Principal Ray 1 (Parallel to Focal)

A ray incident parallel to the optical axis that emerges through the focal point, or appears to diverge from the focal point for a diverging element.

Principal Ray 2 (Focal to Parallel)

A ray directed through or toward the focal point that emerges parallel to the optical axis.

Principal Ray 3 (Center Ray)

A ray that passes undeviated through a thin lens's optical center, or reflects back along its incident path through a spherical mirror's center of curvature.

Electric Force ($F$)

The force exerted on a charge $q$ immersed in an electric field $E$, defined by the relation $F = qE$.

Point-Charge Electric Field

The field produced by a point charge in vacuum, with magnitude $E = \frac{1}{4\pi\epsilon_0}\frac{|q|}{r^2}$, directed radially outward from positive charges and inward toward negative charges.

Parallel-Plate Electric Field

The uniform field between two oppositely charged plates, given by $E_\parallel = \frac{q}{\epsilon A}$, where $\frac{q}{A}$ is the magnitude of the surface charge density.

Point-Charge Electric Potential ($V$)

The scalar potential in vacuum defined by $V = \frac{1}{4\pi\epsilon_0}\frac{q}{r}$, assuming zero potential at infinity and retaining the algebraic sign of the source charge.

Electric Potential Energy Difference ($\Delta U$)

The change in electrostatic potential energy when a charge $q$ moves through an electric potential difference $\Delta V$, calculated as $\Delta U = q\Delta V$.

Electron-Volt ($\text{eV}$)

A unit of energy equal to $1.602 \times 10^{-19}\,\text{J}$, representing the kinetic energy change of an elementary charge accelerated across a potential difference of one volt.