light Flashcards
first law of reflection
incident ray, reflected ray and normal at the point of incidence all lie in the same plane
second law of reflection
angle of incidence is equal to angle of reflection (i=r)
refraction
bending of light as light passes from one optical medium to another
first law of refraction
incident ray, refracted ray and normal all lie in the same plane
second law of refraction
snell’s law
for two given media the ratio of the sine of angle of incidence to the sine of angle of refraction is a constant (n=sin i/sin r)
refractive index (n)
ratio of speed of light in vacuum to the speed of light in the medium
critical angle (c)
angle of incidence in an optically denser medium for which angle of refraction in the optically less dense medium is 90 degrees
total internal reflection
complete reflection of a light ray inside an optically denser medium at its boundary with an optically less dense medium
focal length
distance between the optical centre and the focal point