| what happens to critical angle as refractive index of a substance increases | critical angle decreases |
| NA | NA |
| what is refraction | when the speed and wavelength of a wave changes upon going from one medium to another of different densities
(frequency never changes, direction changes sometimes) |
| what is meant by refractive index | a measure of the ability of the substance to change the direction of a beam of light |
| what is the relationship between refractive index and the two media used | n=sinθ1/sinθ2
where n is refractive index
medium 1 is air/the less dense medium
medium 2 is the material/the more dense medium |
| what is meant by absolute refractive index of a medium | the ratio of the speed of light in a vacuum to the speed of light in that medium |
| what experiment could be used to determine the refractive index of a medium | shine a ray of light though a glass block
a range of angles of incidence and angles of refraction should be obtained
for each angle recorded, the sin of the angle should be calculated
then a graph can be plotted of sinθ1 against sinθ2
the gradient of the graph will be the refractive index of the material |
| what three formulas can be used to calculate the refractive index of a material | sinθ1/sinθ2
λ1/λ2
v1/v2
(sinθ1/sinθ2 = λ1/λ2 = v1/v2) |
| what is refractive index dependent on | frequency of light
the higher the frequency of light, the greater the refractive index |
| what is the critical angle | the angle of incidence which results in an angle of refraction which is exactly 90 degrees |
| what is total internal reflection | when no refraction occurs and is reflected inside the block at angles of incidence greater than the critical angle |
| what is the relationship between critical angle and the absolute refractive index of a medium | sinθc=1/n
where sinθc is critical angle
n is absolute refractive index |
| does frequency of light change when moving from one medium to another | no |
| what is the relationship between refractive index of a medium and density of that medium | higher the refractive index, more dense the medium is |
| what happens to wavelength when moving from one medium to another | it does the same as speed
if speed increases from one medium to another ,wavelength will also increase |
| why does green light refract more than red light | green light has a greaater frequency
the higher the frequency the higher the refractive index
theefore green light has a greater refractive index |
| what happens to critical angle as refractive index of a substance increases | critical angle decreases |
