| A statement of the principle of superposition is: | When 2 or more waves meet at a point, the resultant displacement is the algebraic sum of the displacements of the individual waves |
| What is diffraction? | Spreading of a wave as it passes through a gap or around a edge |
| When are diffraction effects the greatest | when waves pass through a gap with a width roughly equal to their wavelength of the waves |
| When 2 waves arrive completely out of phase or in antiphase with one another. What happens | There is a cancelling out, and the resultant wave has 0 amplitude |
| What is a example of constructive interference? | Where 2 waves arrive at a point in phase with one another so they add up. |
| Define path difference | Extra distance travelled by one of the waves compared with the other |
| For constructive interference the path difference is ... | a whole number of wavelengths |
| Fir destructive interference the path difference is ... | an odd number of half wavelengths |
| Coherent sources emit waves that have a ........ | Constant phase difference |
| What is the double-slit equation | Wavelength = (separation between the centres of the slits ✖️ separation between the centres of adjacent bright (or dark) fringes ) ➗ distance between the slits and the screen |
| What do transmission diffraction gratings consist of? | Large number of equally spaced lines ruled on a glass or plastic side. Each line is capable of diffreacting the incident light |
| What does reflection diffraction grating consist of? | Lines made on a reflecting surface so that lightis both reflected and diffracted by the grating |
| What is a everyday example of a reflection diffraction grating | Shiny surface of a CD |
| What is the equation for a diffraction grating? | d sinθ = n(wavelength) |
| What is splitting of light known as | dispersion |
