Refraction and Lens Lecture Flashcards
the incident ray, refracted ray, and the normal ray at the point of incidence all lie in the same plane
laws of refractio
states that the ratio of the sines of the angles of incidence and refraction is equivalent to the phase velocities in two media or equivalent to the reciprocal of the ratio of the indices of refraction
snell’s law
the ratio of the sines of the angles of incidence and refraction is equivalent to what
phase velocities of two media
reciprocal of the ratio of indices of refrection
mathematically, for an angle of incidence θ1 and the angle of refraction θ:
sin θ1 / sin θ2 = v1 / v2 = n2/n1
bending of light as it goes from one optical medium to another
refraction
when the light rays travels from air to water, the refracted ray bends towards the ___
normal
is the ratio of the velocity of light in a
vacuum (3 x 108 m/s) to the velocity through the material.
index refraction
velocity of light in a vacuum
3x10^8 m/s
why is n>1
the index of refraction will always be greater than 1 since light will have a slower speed in a medium other than a vacuum
index of refraction formula
n = c/v
- The rays of light from a stone get bent (refracted) as they leave the water.
real and apparent depth
is actual distance of an object beneath the surface, as would be measured
by submerging a perfect ruler along with it.
real depth
in a medium is the depth of an object in a denser medium as seen
from the rarer medium. Its value is smaller than the real depth.
apparent depth
a medium in which the speed of light is less.
optically denser
– a medium in which the speed of light is more
optical rarer
As the index of refraction value increases, the optical density ____
increases
As the index of refraction value increases, the optical density increases, and
the speed of light in that material ___
decreases
is the bending of light (also happens with sound, water, and other waves) as it passes from one transparent substance into another
refraction
this bending by ___ makes it possible for us to have lenses, magnifying glasses, prisms, and rainbows
refraction
speed of light in a vacuum
3.00x10^8
when light travels to a material it travels at a ___ speed
different
ratio of the speed of light (c) in a vacuum to the speed of light in a medium (v)
index of refraction
index of refraction formula
n = c/v
c in index of refraction is
speed of light in vacuum
v in n =c/v is the
speed of light in the midum
index of refraction in terms of wavelength
N = λ/λm
λ - wavelength in a vacuum
λm = wavelength in a medium
although the speed changes and the wavelength changes in refraction the ___ will be constant
frequency
formula of frequency wavelength and speed
V = fλ
the relationship between the angles of incidence and refraction and the indices of refraction of the two media
snell’s law
lens that is thicker in the center than the edges
convex lenses
lens that converges (brings together) light rays
convex lenses
forms real images and virtual images depending on the position of the object
convex lenses
lenses that are thicker at the edges and thinner at the center
concave lenses
lens that diverges light rays
concave lenses
convex lenses images are
real and virtual depending on position
concave lenses images are
erect and reduced
common vision defects
farsightedness
nearsightedness
astigmatism
insufficient refractive power to focus rays on retine
farsightedness
excess refractive power focuses rays before they lead in retina
nearsightedness
focuses light in different planes at different points
asymmetric refraction
the ability to see objects clearly which are near but objects far away are blurred
nearsightedness
nearsightedness is also known as
myopia
caused by the fact that rays of light focus in front of the retina of the eye
nearsightedness
nearsightedness is caused by the fact that the rays of light focus in ___ of the retina of the eye
front
correcrted using a diverging lens
myopia
ability to see objects clearly which are far but objects close to the eye appear blurred
farsightedness
farsightedness is also known as
hyeropria
caused by the fact that rays of light focus behind the retina of the eyeco
farsightedness
hyeropia is corrected by using __
converging lens
nearsightedness - fixed with ___ lens
farsightendness - fixed with ___ lens
diverging
converging
to correct nearsightedness, a person will wear ___ glasses
concave
to correct farsightedness a person will wear ___ glasses
convex
which of the following can cause refraction of light
rectangular glass block
prism
concave lenses
all of this
all of this
what is the nature of image formed in a concave lens
always real
always virtual
real or virtual
none of these
always virtual, always diminished, upright
properties of image formed by concave lens
virtual
upright
diminished
when light is incident along the principal axis of a convex lens, where does the refracted ray go?
along the principal axis
what is the correct formula for snell’s law
sin i = sin r
sin i / sin r = constant
sin i > sin r
i/r = constant
sin i / sin r = constant
which of the following can cause dry leaves to burn when sunlight falls on it for a long time
convex
a fish in a lake is looking at a tree on the edge of the lake
how does the tree appear to the fish
shorter
same size
taller
none of these
taller
what happens when light goes from R to D (denser)
bends toward the normal
the refractive index of water, fused quartz, benzene, and ruby are 1.33, 1.46, 1.50, and 1.70 respectively
in which material does light travel the slowest?
ruby
if the focal length of a concave lens is 2.5m, what is the power of the lens?
0.5 D
-0.5D
-0.4D
0.4D
P = 1/f in m = 100/f in cm
-0.4 D
concave lens has positive/negative pwoer
negative
convex lens has positive/negative power
positive
