Superposition, Stationary Waves, Diffraction, and Interference Vocabulary

Vocabulary flashcards based on lecture notes covering superposition, stationary waves, wave diffraction, interference, double-slit experiment, and diffraction gratings.

Principle of Superposition

The principle that when waves of the same type meet at a point, their individual displacements combine to produce a resultant displacement.

Constructive Superposition

Superposition that occurs when waves are in phase, with phase differences of $0$, $2\times\text{pi}$, $4\times\text{pi}$, $6\times\text{pi}\text{ rad}$ (or $0^\text{o}$, $360^\text{o}$), resulting in a maximum resultant displacement.

Destructive Superposition

Superposition that occurs when waves are in antiphase, with phase differences of $\text{pi}$, $3\times\text{pi}$, $5\times\text{pi}$, $7\times\text{pi}\text{ rad}$ (or $180^\text{o}$), resulting in a minimum or zero resultant displacement.

In Phase

The condition of two waves having a phase difference of $0$, $2\times\text{pi}$, $4\times\text{pi}$, $6\times\text{pi}\text{ rad}$ or $0^\text{o}$, $360^\text{o}$, $720^\text{o}$.

Antiphase

The condition of two waves having a phase difference of $\text{pi}$, $3\times\text{pi}$, $5\times\text{pi}$, $7\times\text{pi}\text{ rad}$ or $180^\text{o}$, $540^\text{o}$, $900^\text{o}$.

Stationary Wave

A wave pattern (also called a standing wave) formed by the superposition or interference of two progressive waves traveling in opposite directions with the same frequency, wavelength, and speed.

Node

A position in a stationary wave where destructive superposition occurs, resulting in minimum or zero amplitude.

Antinode

A position in a stationary wave where constructive superposition occurs, resulting in maximum amplitude.

Fundamental Frequency

The lowest frequency wave pattern (first harmonic) capable of forming a standing wave in a given medium or system.

Progressive Wave

A wave that transfers energy from one place to another, where all points over one wavelength have the same amplitude but different phases.

Diffraction

The spreading out of a wave as it passes through a narrow gap, aperture, or around an obstacle.

Coherent Waves

Waves that maintain a constant phase difference, are of the same type, and share the same frequency and wavelength.

Interference of Waves

The phenomenon occurring when two coherent waves meet at a point and superpose, forming a pattern of nodes and antinodes.

Fringe Separation ($x$)

The distance between the centers of adjacent bright or dark interference fringes on a screen.

Diffraction Grating

A slide containing a large number of equally spaced lines (up to $10000\text{ lines/cm}$) used to produce bright, sharp interference maxima according to $d\times\text{sin}(\theta) = n\times\text{lambda}$.

Grating Spacing ($d$)

The distance between adjacent rulings on a diffraction grating, calculated using $d = \frac{1}{k}$, where $k$ is the number of lines per meter.