NAO Course II
Diffraction - ✔️✔️when light is bent without enter another medium; light bending around
doorway into dark room
Index of refraction - ✔️✔️a measure of the amount a ray of light bends when it passes
from one medium to another
n= (speed of light in air)/(speed of light in medium) where "n" is index of refraction
higher index of refraction - ✔️✔️the more it bends light and slower the speed
Electromagnetic wave theory - ✔️✔️light travels in a series of waves moving outward
from light source- James Clark Maxwell
Frequency - ✔️✔️the number of wavelengths that pass by a point each second
Beam - ✔️✔️group of pencils all pointing on light source
Pencil - ✔️✔️group of ray emanating from light source
Visible Light Spectrum Wavelength range - ✔️✔️400nm-700nm
dispersion - ✔️✔️separation of various colored light
UV-C - ✔️✔️200-290nm; absorbed by ozone
UV-B - ✔️✔️290-320nm, absorbed by tear film, cornea, conjunctiva, portions of UV-B
that reaches lens can be cause of cataracts
UV-A - ✔️✔️320-380nm, transmitted by cornea and partly absorbed by lens, ocular
hazard
HEV - ✔️✔️High Energy Visible Light; blue light 380-460nm, factor to age related
macular degeneration
Critical Angle - ✔️✔️the angle of incidence that produces an angle of refraction of 90
degrees
Corpuscular theory of light - ✔️✔️light consists of tiny particles of corpuscles, emitted
by light source and absorbed by the eye- Newton
How to find Critical angle - ✔️✔️Sin(i)= N(2)/N(1) Sine of angle of incidence equals
index of refraction of 2nd medium divided by index of refraction of 1st medium
, Internal Reflection - ✔️✔️when light travels from a medium of greater index to a
medium of lesser index, it is refracted away from the normal
destructive wavelength - ✔️✔️2 waves moving in same direction but crest are opposite
or out of phase; they cancel each other out- no reflection (out of phase)
Constructive wavelength - ✔️✔️waves moving in same direction and crest are at the
same place and time (in phase)- reflection occurs
faster the speed of light - ✔️✔️less light is bent
Refraction - ✔️✔️bending of light as its passing between 2 different refractive mediums
What is the index of refraction in air - ✔️✔️1.0
when light strikes perpendicular angle - ✔️✔️it will be slowed down and will travel
through medium on original path
when light strikes same surface @ an oblique angle - ✔️✔️it will slow down, bend and
will emerge slightly deviated from original path
Angle of Incidence - ✔️✔️angle @ which a ray strikes surface and a line perpendicular
to the surface of "normal" (i)
Angle of refraction - ✔️✔️angle between the ray inside the glass and the line
perpendicular to the surface (r)
Angle of Deviation - ✔️✔️angle from which the line would have extended with no
deviation from where it actually extends "d"
Snell's Law - ✔️✔️n(1)Sin(i)=n(2)Sin(r) where n(1)and n(2)= index of refractive
medium, (i)= angle of incidence, (r)= angle of refraction
Snell's Law simplified - ✔️✔️<i=<r + <d
light traveling from one medium to another, direction of travel is perpendicular or normal
to interface - ✔️✔️it will change speed but NOT direction
Light travels from a less dense material to a denser material @ and angle to normal -
✔️✔️it will bend toward the normal
light travels from denser material to less dense material @ angle to the normal - ✔️✔️it
will bend away from the normal
Diffraction - ✔️✔️when light is bent without enter another medium; light bending around
doorway into dark room
Index of refraction - ✔️✔️a measure of the amount a ray of light bends when it passes
from one medium to another
n= (speed of light in air)/(speed of light in medium) where "n" is index of refraction
higher index of refraction - ✔️✔️the more it bends light and slower the speed
Electromagnetic wave theory - ✔️✔️light travels in a series of waves moving outward
from light source- James Clark Maxwell
Frequency - ✔️✔️the number of wavelengths that pass by a point each second
Beam - ✔️✔️group of pencils all pointing on light source
Pencil - ✔️✔️group of ray emanating from light source
Visible Light Spectrum Wavelength range - ✔️✔️400nm-700nm
dispersion - ✔️✔️separation of various colored light
UV-C - ✔️✔️200-290nm; absorbed by ozone
UV-B - ✔️✔️290-320nm, absorbed by tear film, cornea, conjunctiva, portions of UV-B
that reaches lens can be cause of cataracts
UV-A - ✔️✔️320-380nm, transmitted by cornea and partly absorbed by lens, ocular
hazard
HEV - ✔️✔️High Energy Visible Light; blue light 380-460nm, factor to age related
macular degeneration
Critical Angle - ✔️✔️the angle of incidence that produces an angle of refraction of 90
degrees
Corpuscular theory of light - ✔️✔️light consists of tiny particles of corpuscles, emitted
by light source and absorbed by the eye- Newton
How to find Critical angle - ✔️✔️Sin(i)= N(2)/N(1) Sine of angle of incidence equals
index of refraction of 2nd medium divided by index of refraction of 1st medium
, Internal Reflection - ✔️✔️when light travels from a medium of greater index to a
medium of lesser index, it is refracted away from the normal
destructive wavelength - ✔️✔️2 waves moving in same direction but crest are opposite
or out of phase; they cancel each other out- no reflection (out of phase)
Constructive wavelength - ✔️✔️waves moving in same direction and crest are at the
same place and time (in phase)- reflection occurs
faster the speed of light - ✔️✔️less light is bent
Refraction - ✔️✔️bending of light as its passing between 2 different refractive mediums
What is the index of refraction in air - ✔️✔️1.0
when light strikes perpendicular angle - ✔️✔️it will be slowed down and will travel
through medium on original path
when light strikes same surface @ an oblique angle - ✔️✔️it will slow down, bend and
will emerge slightly deviated from original path
Angle of Incidence - ✔️✔️angle @ which a ray strikes surface and a line perpendicular
to the surface of "normal" (i)
Angle of refraction - ✔️✔️angle between the ray inside the glass and the line
perpendicular to the surface (r)
Angle of Deviation - ✔️✔️angle from which the line would have extended with no
deviation from where it actually extends "d"
Snell's Law - ✔️✔️n(1)Sin(i)=n(2)Sin(r) where n(1)and n(2)= index of refractive
medium, (i)= angle of incidence, (r)= angle of refraction
Snell's Law simplified - ✔️✔️<i=<r + <d
light traveling from one medium to another, direction of travel is perpendicular or normal
to interface - ✔️✔️it will change speed but NOT direction
Light travels from a less dense material to a denser material @ and angle to normal -
✔️✔️it will bend toward the normal
light travels from denser material to less dense material @ angle to the normal - ✔️✔️it
will bend away from the normal
