ray optics Flashcards
wht is ray optics
- branch of phys
- deal with beahviour of light
path of light changes when?
- medium changes
visible spectrum
- EMW raditaion
- 36 - 7800 angstrong
eyes are most sensitive to which colour
- yellowish green
- 5550 A
- lemda =
- V =
- lemda = VT
- V = n lemda
chnges that occur to light with chnage in medium
- speef of light chnage
- wavelength of light chnages
- frequency constant
frequency is dependent on ?
source of light
light rays spectrum
no. line
- gamma
- X -rays
- UV rays
- visible
- Infrared rays
- micro waves
- radio waves
reflection of light diagream
notes pg 2
Laws of reflection
- incident ray, reflected ray, normal
- at point of incidence
- will be in same plane
- { icap . [ncap *r cap ]}= 0
- incident ray, reflected ray, normal
- angle of refelction = angle of incidence
how do we decide which types of object ? and types of obejct
decided by incident rays
1. real point - diverging rays from the obj
2. virtual point - convereging rays
how it is decided? image types?
it is decided by reflected and refracted ray
1. real image - diverging towards the image
2. virtual - converging
propeties of a plane mirror
- perfect plan reflecting surface
- lateral inverion of image formed’3==
- lateral maginification = +1
- forms real image of virtual object or VV
- acts as perpendicular bisectoor
- exapnds object in plane mirrror
rotataion of reflecting ray
1. when incident ray rotated with theta angle
2. when mirror rotated with theta angle
rotataion of reflecting ray
1. when incident ray rotated with theta angle - reflected ray rotate with theta angle in OPP directin
2. when mirror rotated with theta angle - reflected ray rotate 2theta in same directin
value of theta
0 = arc lenght / radius
deviation in plane mirror
delata = 180 degree - 2i
- anticlockwise
deviatin through two mirror at an angle 0
delta 1 = 180 - 2alpha
delta 2 = 180 - 2beta
delta net = 360 - 2theta
no of images formed
1. 2 parallel mirror
2. 2 mirror kept at an angle
- infinty
- even- n = m-1
odd - [ obj placed at bisector ] n = m-1
odd - [obj not at bisector ]
n = m
m = ?
n = ?
m - 360 / theta
n = no. of images
page 9 to calculate images
velocity of image
1. obj moving parallel to mirror =
2. obj moving perpendicula to mirror =
velocity of image
1. obj moving parallel to mirror = Vi= Vo
2. obj moving perpendicula to mirror = Vim = -Vom
formula of Vi ?
Vi = 2Vm -Vo
wht is a spherical mirror
part of spehere
pole -
principal axis -
radius of curvature -
focus -
focal length -
focal length depnds on ____________ for mirror
pole - mid point of curved surface
principal axis - line perpendicular to the pole passing from centre of curvature
radius of curvature - dist from centre to circumference
focus - point where rays paralel to PA cross on principal axis
focal length - distance from pole to focus
focal length depnds on _radius _of curvature _ for mirror and remains same for vibgyor
marginal rays -
paraaxial rays -
marginal rays - rays away from PA
paraaxial rays - rays near PA
spherical abbreviation
it is a defect
- for remiving it we use paraxial rays and samll size mirror
sign convention for mirror
f for -
1. concave -
2. convex -
sign convention for mirror
f for -
1. concave - -ve
2. convex - +ve
- mirror formula
- v =
- 1/f = 1/u +1/v
- v = uf/ u - f
linear magnification
- m = -v/u = f/f - u= hi/ho
longitudianl magnification
- m = li/lo
- m = m^2 [ if obj small]
superficial magnificatin
- m = ai/ao
- m = m^2
ao = lb
ai = li bi
li = mlo
bi = m*bo
image formation of mirror table CONCAVE/ convex
notes 16
in convex mirror we can get real image when ?
real image when virtual object kept btween F and P
velocity of image [ curved mirror ]
1. object moving along PA
2. obj moving perpendicular to PA
- object moving along PA
Vim = -m^2 Vom - obj moving perpendicular to PA
Vi = mVo
newtons formula
f = root x1*x2
x1 - obj from focus
x2 = image form focus dsitance `
refraction
Rare to dense -
dense to rare -
light travel from one medium to another mideium
then light ray deviate from its path
- RTDN
- DTRA
laws of refractions
- mew1sinr = mew2sinr [ snells law]
- incident ray refracted ray and normal in same plane
formula for refraction through multiple layers
mew1 sine i = mew2 sin r1
mew2 sin r1 = mew 3 sin r2
mew 3 sin r2 = mew4 sine e
mew1 sine i = mew4 sine e
relative refractive index formula
mew relative = 1 mew 2 = mew 2 / mew 1
Total internal refraction
- sin theta c =
- theta c =
- light travel from densre to rarer medium
- delta = r - i
- delta = 180 - 2i
- sin theta c = mewr / mew d
- theta c = sin inverse 1/ mew
tan theta for bulb place in depth of water and a floating disc kept upan the bulb find min diameter of disc
tan theta c = r/ h
r = h tand theta c
in vibgyor denser to rarer
- which light move to which medium
- above yellow rarer
- below yelloe denser
application of TIR
- optical fibre
- brilliance of diamond
- optical looming and mirage
- prism
- prism angle
- A =
- delta =
for minimun deviation - i =
- r1 =
- A =
- delta min =
- prsim angle
- delta min=
- prism - it has two refracting surface
- prism angle - angle between 2 refracting surface
- A = r1 +r2
- delta = i + e - A
for minimun deviation - i = e
- r1 = r2 = r
- A = 2r
- delta min = 2i - A
- prsim angle < 10 degree
- delta min= [mew - 1] A
- snells law of xy surface =
- snells law for xz surface =
- mew for minimu deviation =
- snells law of xy surface = 1 sin i = 1 sin e
- snells law for xz surface = new sin r2 = 1 sine e
- mew for minimu deviation = sin 1/ sin r
= sin [delta min + A/2 ] / sin A/2
