Deck1: Wave Basics & Superposition

What is the definition of a transverse wave?

A wave where the oscillations are perpendicular to the direction of energy transfer.

What is a longitudinal wave?

A wave where the oscillations are parallel to the direction of energy transfer.

What is displacement in wave terminology?

The distance a point has moved from its equilibrium position.

Define amplitude.

The maximum displacement of a point on the wave from its equilibrium position.

Define wavelength.

The distance between two adjacent points in phase on a wave, e.g., crest to crest.

What is the wave period?

The time taken for one complete oscillation.

What is frequency?

The number of complete wave cycles per second, measured in Hz.

State the wave equation.

v = fλ, where v is speed, f is frequency, and λ is wavelength.

What is phase difference?

The difference in phase between two points on a wave, measured in degrees or radians.

What is meant by 'in phase'?

Points that are oscillating together and have a phase difference of 0 or multiples of 2π.

What is meant by 'out of phase'?

Points that are not oscillating together, with a phase difference not equal to 0 or 2π.

What is reflection?

When a wave bounces back after hitting a barrier.

What is diffraction?

The spreading of waves when they pass through a gap or around an obstacle.

When is diffraction most significant?

When the gap size is comparable to the wavelength.

What changes during reflection?

Only the direction of the wave changes; frequency, wavelength, and speed remain the same.

What is refraction?

The change in direction of a wave as it passes from one medium to another due to a change in speed.

What happens to wave speed and wavelength when entering a denser medium?

Wave speed decreases, and wavelength shortens.

What is the principle of superposition?

When two or more waves meet, the resultant displacement is the sum of the individual displacements.

What is constructive interference?

When two waves meet in phase and reinforce each other, increasing amplitude.

What is destructive interference?

When two waves meet out of phase and cancel each other out, reducing amplitude.

What does it mean for waves to be coherent?

Waves that have a constant phase difference and the same frequency.

What is an example of interference in a double-slit experiment?

Bright and dark fringes on a screen due to constructive and destructive interference.

What determines the fringe spacing in a double-slit setup?

Wavelength, slit separation, and distance to the screen.

Formula for path difference in constructive interference?

Δ = nλ, where n is an integer.

Formula for path difference in destructive interference?

Δ = (n + ½)λ, where n is an integer.

Why is coherence important in interference experiments?

To maintain stable and predictable interference patterns.

What condition must be met for clear stationary or interference patterns?

Sources must be coherent and have similar amplitudes.