Reflection and Refraction Flashcards
The laws of reflection 1)
The angle of incidence i = the angle of reflection r
The laws of reflection 2)
The incident ray, the reflected ray and the normal all lie in the same place
Snells law for refraction
Sin i / sin r = n
Sin of the angle of incidence / sin of the angle of refraction = the refractive index
The refractive index of a medium n = the
Speed of light in a vacuum / speed of light in the medium
Diverging lenses form ______ _________ images
Only virtual
Converging lenses can form ______ or ________ images
Virtual Real
Total internal reflection occurs when…
The angle of incidence is greater than the critical angle
The critical angle c for a medium is related to the refractive index n by
n = 1/sinc
The lens equation
1/objective distance + 1/image distance = 1/focal length
Objective distance is
The distance from the object to the lens
Image distance is
The distance from the image to the lens
Negative values refer to virtual images
Focal length is
The length from the lens to the principle focus
Negative values of f refer to diverging lens’
The reciprocal of the focal length in meters gives the_____of the lens measured in _______
Power dioptres
Positive powered lenses are
Converging
Negative power lenses are
Diverging
