Wave phase difference
We can describe the position of a wave using an angle: that’s called the phase of the wave.
The start of the wave is at
The next full cycle of the wave happens at
This means that the phase difference between two peaks,
troughs or wave cycles is
Phase and antiphase
-
If the phase difference between two points on a wave is
2\pi radians:- the points are in phase
- the points are doing exactly the same thing
-
If the phase difference between two points on a wave is
\pi radians:- the points are in antiphase
- the points are doing opposite things
Moving one wave by half a wavelength
If we move along a wave by half a wavelength, we move by a phase difference of
This means that if we start at a peak, and move half a wavelength along the wave, we’ll end up at a trough, for example.
- If the waves were previously in phase, they will now be in antiphase.
- If the waves were previously in antiphase, they will now be in phase.
flashcards
| Question | Answer |
|---|---|
| What is the term for describing the position of a wave using an angle? | Phase |
| What is the phase angle at the start of a wave? | |
| What is the phase angle at the end of a full wave cycle? | |
| What is the phase difference between two peaks, troughs, or wave cycles? | |
| If the phase difference between two points on a wave is | The points are in phase and are doing exactly the same thing |
| If the phase difference between two points on a wave is | The points are in antiphase and are doing opposite things |
| What phase difference corresponds to moving along a wave by half a wavelength? | |
| If you start at a peak and move half a wavelength along the wave, where do you end up? | At a trough |
| If two waves were previously in phase, what is their phase relationship after moving one wave by half a wavelength? | They will be in antiphase |
| If two waves were previously in antiphase, what is their phase relationship after moving one wave by half a wavelength? | They will be in phase |