P3.2.2 & 3.2.4 - Refraction & Light Dispersion Flashcards
What is refraction? [2]
The bending of light as it travels from one medium to another
When do refraction occur? [2]
when the speed of light changes when it is travelling from one medium to another.
What does a change in density/ medium lead to a change in? [2]
- change of speed
- change of overall direction of the wave
When do waves not bend? [1]
when there is homogenity (uniformity) (being the same)
What type of medium do you need to bend light? [1]
Transparent medium
What is a beam? [1]
consists of many rays of light
What is the reason why light bends? [1]
The change of speed of light
What does density cause? [1]
refraction of light
What is normal density? [1]
heaviness or lightness of a material
What is optical density? [1]
how much a material is able to slow down light
How is no refraction caused? [2]
If light travels perpendicular from one medium to another.
What happens to the frequency, when medium changes? [1]
ALWAYS stays the same
What happens to the speed if you go from denser to rare medium? [1]
It gets faster
What happens to the speed if you go from rarer medium to denser medium? [1]
It slows down
What is the formula for REFRACTIVE INDEX? [2]
n = sin i / sin r
What is the full form of the formula for refractive index? [2]
refractive index = sin of angle of incidence / sin of refracted angle
What will be the refracted index value if the material is denser than air? [1]
More than 1
Which medium is denser than air? [1]
Water
What is the definition of refractive index? [2]
the ratio of the speeds of a wave in two different regions
What is another formula for refractive index in terms of speed of light? [2]
n = speed of light in air or vacuum / speed of light in the medium
What happens to the refracted line if it goes from rarer to denser medium in terms of the normal? [1]
It gets closer to the normal
What happens to the refracted line if it goes from denser to rarer medium in terms of the normal? [1]
It gets further away to the normal
What is the speed of light in air or in a vacuum? [2]
3 x 10^8
What is the speed of light in glass? [2]
2 × 10^8
What is the concept of deviation in a prism? [3]
When light is refracted by a prism, comes out in different direction because the sides of a prism are not parallel
What is the effect of dispersion in a prism? [2]
light is passed through a prism, it splits into a range of colours called a spectrum
What are wavefronts? [1]
imaginary planes perpendicular to the crests or the troughs
What is a wavelength in terms of wavefronts? [1]
the distance between two wavefronts
What happens when the medium changes from rarer to denser in terms of wavelength and frequency? [2]
- wavelength changes
- frequency stays the same
What is a ray? [1]
a line perpendicular to wavefronts
