ray optics

Question 1

wht is ray optics

Answer 1

• branch of phys
• deal with beahviour of light

Question 2

path of light changes when?

Answer 2

• medium changes

Question 3

visible spectrum

Answer 3

• EMW raditaion
• 36 - 7800 angstrong

Question 4

eyes are most sensitive to which colour

Answer 4

• yellowish green
• 5550 A

Question 5

1. lemda =
2. V =

Answer 5

1. lemda = VT
2. V = n lemda

Question 6

chnges that occur to light with chnage in medium

Answer 6

• speef of light chnage
• wavelength of light chnages
• frequency constant

Question 7

frequency is dependent on ?

Answer 7

source of light

Question 8

light rays spectrum
no. line

Answer 8

1. gamma
2. X -rays
3. UV rays
4. visible
5. Infrared rays
6. micro waves
7. radio waves

Question 9

reflection of light diagream

Answer 9

notes pg 2

Question 10

Laws of reflection

Answer 10

1. • incident ray, reflected ray, normal
     - at point of incidence
     - will be in same plane
     - { icap . [ncap *r cap ]}= 0
2. angle of refelction = angle of incidence

Question 11

how do we decide which types of object ? and types of obejct

Answer 11

decided by incident rays
1. real point - diverging rays from the obj
2. virtual point - convereging rays

Question 12

how it is decided? image types?

Answer 12

it is decided by reflected and refracted ray
1. real image - diverging towards the image
2. virtual - converging

Question 13

propeties of a plane mirror

Answer 13

1. perfect plan reflecting surface
2. lateral inverion of image formed’3==
3. lateral maginification = +1
4. forms real image of virtual object or VV
5. acts as perpendicular bisectoor
6. exapnds object in plane mirrror

Question 14

rotataion of reflecting ray
1. when incident ray rotated with theta angle
2. when mirror rotated with theta angle

Answer 14

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

Question 15

value of theta

Answer 15

0 = arc lenght / radius

Question 16

deviation in plane mirror

Answer 16

delata = 180 degree - 2i
- anticlockwise

Question 17

deviatin through two mirror at an angle 0

Answer 17

delta 1 = 180 - 2alpha
delta 2 = 180 - 2beta
delta net = 360 - 2theta

Question 18

no of images formed
1. 2 parallel mirror
2. 2 mirror kept at an angle

Answer 18

1. infinty
2. even- n = m-1
   odd - [ obj placed at bisector ] n = m-1
   odd - [obj not at bisector ]
   n = m

Question 19

m = ?
n = ?

Answer 19

m - 360 / theta
n = no. of images

page 9 to calculate images

Question 20

velocity of image
1. obj moving parallel to mirror =
2. obj moving perpendicula to mirror =

Answer 20

velocity of image
1. obj moving parallel to mirror = Vi= Vo
2. obj moving perpendicula to mirror = Vim = -Vom

Question 21

formula of Vi ?

Answer 21

Vi = 2Vm -Vo

Question 22

wht is a spherical mirror

Answer 22

part of spehere

Question 23

pole -
principal axis -
radius of curvature -
focus -
focal length -
focal length depnds on ____________ for mirror

Answer 23

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

Question 24

marginal rays -
paraaxial rays -

Answer 24

marginal rays - rays away from PA
paraaxial rays - rays near PA

Question 25

spherical abbreviation

Answer 25

it is a defect - for remiving it we use paraxial rays and samll size mirror

Question 26

sign convention for mirror f for - 1. concave - 2. convex -

Answer 26

sign convention for mirror f for - 1. concave - -ve 2. convex - +ve

Question 27

1. mirror formula 2. v =

Answer 27

1. 1/f = 1/u +1/v 2. v = uf/ u - f

Question 28

linear magnification

Answer 28

1. m = -v/u = f/f - u= hi/ho

Question 29

longitudianl magnification

Answer 29

1. m = li/lo 2. m = m^2 [ if obj small]

Question 30

superficial magnificatin

Answer 30

1. m = ai/ao 2. m = m^2 ao = lb ai = li *bi li = m*lo bi = m*bo

Question 31

image formation of mirror table CONCAVE/ convex

Answer 31

notes 16

Question 32

in convex mirror we can get real image when ?

Answer 32

real image when virtual object kept btween F and P

Question 33

velocity of image [ curved mirror ] 1. object moving along PA 2. obj moving perpendicular to PA

Answer 33

1. object moving along PA Vim = -m^2 Vom 2. obj moving perpendicular to PA Vi = mVo

Question 34

newtons formula

Answer 34

f = root x1*x2 x1 - obj from focus x2 = image form focus dsitance `

Question 35

refraction Rare to dense - dense to rare -

Answer 35

light travel from one medium to another mideium then light ray deviate from its path - RTDN - DTRA

Question 36

laws of refractions

Answer 36

1. mew1sinr = mew2sinr [ snells law] 2. incident ray refracted ray and normal in same plane

Question 37

formula for refraction through multiple layers

Answer 37

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

Question 38

relative refractive index formula

Answer 38

mew relative = 1 mew 2 = mew 2 / mew 1

Question 39

Total internal refraction - sin theta c = - theta c =

Answer 39

- 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

Question 40

tan theta for bulb place in depth of water and a floating disc kept upan the bulb find min diameter of disc

Answer 40

tan theta c = r/ h r = h tand theta c

Question 41

in vibgyor denser to rarer - which light move to which medium

Answer 41

- above yellow rarer - below yelloe denser

Question 42

application of TIR

Answer 42

1. optical fibre 2. brilliance of diamond 3. optical looming and mirage

Question 43

1. prism 2. prism angle 3. A = 4. delta = for minimun deviation 1. i = 2. r1 = 3. A = 4. delta min = 5. prsim angle 6. delta min=

Answer 43

1. prism - it has two refracting surface 2. prism angle - angle between 2 refracting surface 3. A = r1 +r2 4. delta = i + e - A for minimun deviation 1. i = e 2. r1 = r2 = r 3. A = 2r 4. delta min = 2i - A 5. prsim angle < 10 degree 6. delta min= [mew - 1] A

Question 44

1. snells law of xy surface = 2. snells law for xz surface = 3. mew for minimu deviation =

Answer 44

1. snells law of xy surface = 1 sin i = 1 sin e 2. snells law for xz surface = new sin r2 = 1 sine e 3. mew for minimu deviation = sin 1/ sin r = sin [delta min + A/2 ] / sin A/2