Wave Interference Flashcards
(11 cards)
What are wave-fronts?
Lines (or planes in 3D) drawn to join points in a wave where all the oscillations are in phase
Wave-fronts are spaced one wavelength apart and move in a direction perpendicular to the wave-front.
How far apart are wave-fronts?
One wavelength apart
Each wave-front represents points in the wave that oscillate in unison.
In which direction do wave-fronts move?
Forward in a direction perpendicular to the wave-front
This direction is along a ‘ray’ line.
What is the phase difference between two successive wave-fronts?
360° or 2π radians
This represents one complete cycle of wave oscillation.
What is interference in wave physics?
A detectable pattern of different strengths (amplitudes) of wave oscillation
Examples include large and small water ripples, light and dark fringes, loud and soft sounds, and good and poor radio reception.
What causes interference in waves?
Waves from different sources crossing and adding together
This process is known as superposition.
What condition must be met for interference patterns to occur?
The wave sources must be coherent
Coherence means they have the same frequency and a fixed phase relationship.
Why can’t detectors directly measure the frequency and phase of light?
No detector is fast enough to do so
Interference experiments are used to explore the coherence of light.
What role does the principle of superposition play in sound amplitude experiments?
Amplitudes add together mathematically
This explains why a microphone picks up sound even at minimum resultant amplitude points.
Fill in the blank: Wave interference becomes really useful in explaining _______.
interference
True or False: Interference patterns can occur with incoherent wave sources.
False
Interference patterns only occur with coherent wave sources.
