Light Flashcards
define refractive index of a medium
ratio between the speed of light in a vacuum and speed of light in a medium
formula for refractive index
n= sin i/sin r
n-refractive index
sin i-angle of incidence
sin r- angle of refraction
formula for critical angle related to reflective index
n= 1/sin c
Define critical angle
waves going from a dense medium to a less dense medium that speed up at the boundary between them
Define refractive index
a measure of how much speed of light changes when it enters a denser medium than air
internal vs total internal reflection
- Total Internal reflection occurs only when light travels from a denser medium to a lighter medium.
- Reflection occurs for any angle of incidence between 0° and 90°. Total internal reflection occurs only if the angle of incidence is more than the critical angle between the two media.
uses of optical fibres
endoscope & inside-body flexible cameras - Medicine
high speed data transfer - Communications
Describe an optical fibre
it is a long thin rod surrounded by cladding which uses total internal reflection to transfer information by light, even when bent
characteristics of magnifying glass
- virtual
- enlarged
- upright
which colour has the largest wavelength
red
which colour has the smallest wavelength
violet
define monochromatic
light of a single wavelength or frequency
features of optical image further than 2F
- real
- diminished
- inverted
features of optical image between 2F and F
- real
- enlarged
- inverted
features of optical image exactly on 2F
- real
- same size
- inverted
