Geometrical Optics Flashcards
draw diagram of reflection.
what is point of incidence?
state laws of reflection?
what is a spherical mirror?
if the inside/outside surface of a sphere is polished, then it is a _____ and _______ mirror.
a spherical mirror has the shape of section sliced from the surface of a sphere.
inside concave
outside convex
centre of curvature?
radius?
pole?
principal axis?
focal length? SI unit
principal focus?
for a lens
the point at which the rays passing parallel to the principle converge in the case of a convex lens and appear to diverge virtually in the case of a concave lens.
pg 60
derive spherical mirror equation.
what is spherical mirror equation? state formula?
a precise mathematical relationship b/w the object distance & the image distance for a given mirror.
and focal length
what is magnification? formula?
mirror
ratio of the height of the image to the height of the object is defined as the magnification.
hi/ ho
sign convention of mirror equations?
pg 50
when will ray of light bent towards normal? angle of refraction will be less or more?
when will ray of light bent away normal?
when it enters from optically rarer to denser medium
less
vice versa
define refraction?
what causes it?
- the change in the direction of light when it pases from one medium through another medium of different densities.
- caused due to change in the speed of light
refractive index?
formula?
symbol?
unit?
value for optical medium?
ratio of speed of light in vaccum to the speed of light in specific medium is constant and called index of refraction.
n = c / v
n
unitless
always greater or = 1
c = speed of light in vacuum 3 x 10 ^8 m/s
what does refractive index tell us?
value of c?
large value equals higher bending of light.
c = speed of light in vacuum 3 x 10 ^8 m/s
conditions for TIR?
2
what is TIR?
when incident angle is greater than critical angle, all the incident light is reflected at the boundry back into the optically denser medium.
how to derive equation for cirtical angle?
use snell’s law
θ1 = θc
θ2 = 90
sinθc = n2/n1
pg 56
parts of optical fibre?
how light doesn’t get out of boundry?what protects the core from what?
how tir used in light propagation through optical fibres?
boundry between the core and cladding
what is angle of deviation? draw diagram to demonstrate.
the change in the direction of light as it passes thorugh the glass is called its deviation & is measured as angle of deviation. θ dev
what is dispersion of light?
why does it happen?
refractive index is greater and smaller for ____ light?
pg 58
what is lens?
types?
shape of types? why are they called that?
what is optical centre?
centre of curvature of lens?
focal length of lens?
what is the lens equation?
this is for lenses
centre point of lens O
no real so 2F is used
distance from optical centre to focal point
mathematical relationship b/w the object distance & the image distance for a given lens.
pg 60
describe the passage of light through convex and concave lens? by drawing a diagram
pg 60
what does lens equation do?
pg 62
sign convention for lenses
focal length of convex lens?
if object is on the left side of the lens?
sign when image is on the left side of the lens or same side as the object
+
+
-
pg 63
define power of a lens? unit? formula
the degree of convergence or divergence of light falling on lens is called power of lens Diopters or meter inverse
D= 1/f
f = focal length
what is magnfiying power?
formula? unit?
symbol?
pg 65
unitless
what is resolving power?
what should be done for clear image?
what is accommodation?
what is focal point of the eye?
when are ciliary muscles relaxed? what happens to the lens?
when are they contracted? what happens to the lens?
image must be on light sensitive retina
process of adjusting the eye’s focal length.
the retina
pg 67
what is near point? aka?
the shortest distance at which the eye can focus a sharp image of an object.
for young adults 25 cm
least distance of distinct vision
what is short-sightedness?
scientific name?
where is the image formed?
what is done to fix it? which lens? why?
myopia
the images of distant objects is focused in front of retina
concave/ diverging lens
what is long-sightedness?
scientific name?
where is the image formed?
what is done to fix it? which lens? why?
hyperopia
convex/ converging lens
to converge at retina and not beyond it
draw ray diagram of simple microscope and state its resolving power?
formula for angula magnifiction for 2 things?
pg 69
compound micrscope magnification relation?
name the terms?
reasons for the formula?
what will the answer of relation tell us?
how many times the image has been magnified
draw ray diagram of telescope and mention its magnifying power? explain the formula?
state Snell’s law and formula for it? label
constant of proportionality is _______.
what is formula when incident medium is air?
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant for the pair of the given media.
n1 sinθ1 = n2 sinθ2
same as refractive index when incident medium is air or vacuum
if light is moving from denser to rarer medium. will refracted or incident ray be greater?
refracted ray
cz it’ll bend away from normal
pg 55
describe the passage of light through parallel sided transparent material.
pg 52
how can we know the nature of the image while solving?
for mirrors
for lens keep in mind the sign convention for lenses
- first check if its convex or concave
- in di if its - then image is behind the mirror. (virtual)
- if M is + then image is upright/erect
- then compare ho & hi if it becomes smaller that means that image is diminshed vice versa.
u can also use the methods to see if the sign of ur ans r correct or not
but a convex mirror will always form virtual, upright, & diminished images.
rearrange mirror formula to find distance of image.
why objects in the _______ mirror are closer than they appear?
pg 50
convex
cz convex mirror produces an image that is reduced in size, which make the objects look as if its farther away pg 51
the magnification of a convex mirror is always ________, but that of a concave mirror ______________.
concave mirror can never form ________ image.
positive
may be both +ve & -ve
virtual, erect, & diminished atst
ved
concave mirror forms ________ image.
convex mirror forms ________ image
A concave mirror can form 2 different types of images depending on where the object is placed relative to the mirror: real & virtual
A convex mirror always forms virtual, upright, & diminished images, irrespective of the position of the object.
