what is refraction? - Answers the change of direction of waves when they travel across a boundary
when does refraction occur? - Answers when a wave enters a new medium with a different refractive
index
from a less dense medium to a more dense medium light? - Answers bends towards the normal
from a more dense medium to a less dense medium light? - Answers bends away from the normal
what happens to the speed of a wave when it travels from a less dense medium to a more dense one? -
Answers slows down
what properties of a wave change during refraction? - Answers wavelength and speed (never frequency)
what is the refractive index of air? - Answers approximately 1
what does snell's law relate to? - Answers the angle of incidence to the angle of refraction
what is snells law? - Answers n1sinθ1 = n2sinθ2
what is the total internal reflection? - Answers the complete reflection of light within the medium
what are the 2 conditions for refraction? - Answers light must be travelling from a more denser medium
to a less denser medium and the angle of incidence must be greater than the critical angle
what is the critical angle? - Answers the angle of incidence when the angle of refraction is 90 degrees
equation for total internal reflection - Answers sin θ = n2/n1
when does the total internal reflection occur? - Answers when the angle of incidence is greater than the
critical angle
what are the 3 main components that make up optical fibres? - Answers the transparent core (made out
of plastic/glass), a cladding surrounding the core and an outer stealth.
what is the purpose of cladding? - Answers protects the core from damage, adds total internal
reflection, prevents radiation from 'leaking' from one fibre to another
what is the purpose of the outer sheath? - Answers prevents physical damage done to fibre, strengthens
the fibre, protects fibre from any outside scratches
the pulses that are sent along the optic fibre represent what? - Answers a digital signal made up from
zeros and ones
when does material dispersion occur? - Answers when white light is used instead of monochromatic
light