ray optics Flashcards
whAT IS THE WAVELenght of visible light
4000-7500 armstrong
what type of mirror is present in our homes what size of object it shows
plane mirror is present in our homes and it forms virtual image which shows image of same size
difference between virtual and real image
virtual image image can not be taken on a screen it is always erect and light rays appear to meet
on the other hand real image can be taken on screen ther are always inverted and light rays actually meet
concave and convex mirror
when light is incident on cave it is concave
convex mirror image
virtual erect image always diminished security mirror and side view mirror
concave mirror is knowwn as and convex mirror is known as
concave converging convex diverging
mirror formula
1/f=1/u+1/v
magnification for lens and mirror
for mirror m= hi/ho=-v/u
for lens m=v/u
magnification +ve and -ve indicate
+ve magnification is erect image and -ve magnification is inverted image
areal magnification
areal magnification= square of ( linear magnification)
light bending in various medium
light bend away from the normal in rarer medium and towards the normal in denser medium
comment on light ray while refraction
during refraction wavelength changes but frequency remains same or constant. the cause of refraction is different speed of light in dfferent medium
law of refraction
1)incident ray normal and refracted ray all lie on the same plane
2) the ratio of sine of angle of incidnce to and =gle of refration is a lways constant for a given pair of media i.e sini/sinr= mew u
refractive index
it is the ratio of speed of light in vaccum or air to the speed of light in that medium ( absolute refractive index)
ratio of speed of light in medium to medium 2 is called relatove refractive index for ex 1u2
=speed in 1/speed in2= u2 refractive index of2 /u1refractive index of1
velocity is directly propotional to wavelength
w(u)g
refractive index of glass w.r.t to water= ug/uw
u glass=1.5 u water =1.33/=4/3
