G10 Refraction of Light Flashcards
occurs due to the differences in density between two media
Refraction
is the main reason why we see objects around us
Refraction
Light reflected by objects around us enters the eye and is refracted by the _ of the eye.
lens
I. As light enters the pupil, the cornea and lens of the eye refract the light rays to focus it on the retina.
II. The brain will interpret the image.
As light enters the pupil, the _ and _ of the eye refract the light rays to focus it on the retina.
cornea and lens
When waves are refracted, they change their _ as they pass across the boundary between two media.
speed
This results in their change in direction.
Refraction
The angle of _ and the angle of _ should always be measured from the normal line.
incidence, refraction
The extent of change in the direction of light depends on _.
refractive index
This causes a change in the speed of light. The greater the _ _ of the substance, the greater the light’s _.
refractive index, refraction
Refractive index is also called as the _ _.
optical density
When the speed of light through the vacuum increases, it will move _ from the normal line.
When the speed of light through the vacuum decreases, it will move towards the normal line.
away
When the speed of light through the vacuum increases, it will move _ from the normal line.
When the speed of light through the vacuum decreases, it will move _ the normal line.
away, towards
is used to predict the angle of refraction from the angle of incidence and the refractive index of the material.
Snell’s Law
is the index of refraction of a material
Snell’s Law
n
are the angles of incidence and angle of refraction respectively
(Snell’s Law)
θi and θr
using the speed of light to find refractive index
speed of light in a vacuum/ speed of light in a material
bulge at the middle and thins at the edges
bulge at the middle and thins at the edges
bulge at the middle and thins at the edges
Converging lenses
Converging lenses are also called
convex lenses
This lens focuses parallel light rays from _ to a single converging point.
infinity
biconvex
plano convex
meniscus convex
the center of the lens
Vertex
the horizontal line that intersects the vertex
Principal axis
point where all of the light rays are focused
Focal point (F)
distance from the focal point to the vertex
Focal length
twice the distance of the focal point from the vertex. It is the radius of the circle which the lens was derived from.
Center of curvature (2F)
LOST
the image’s position relative to the object and the lens
Location
Orientation
either upright or inverted
Size
can be reduced, magnified, or the same as the object
Type
can either be real or virtual
First, a simple outline of the lens is drawn with a horizontal axis passing through the middle of it or the principal axis.
The positions of the focuses F, with equal distances from the lens, on both sides of the lens was marked.
The first ray was drawn parallel to the axis from the top of the object to the lens and deflected down towards the focal point. This is known as the principal ray.
The second ray is drawn passing through the focal point to the lens. This ray is then deflected through the lens in a direction parallel to the principal axis. This is known as the focal ray.
The third ray was drawn straight from the top of the arrow (the object) through the middle of the lens without deflection. This is also known as the central ray.
The image is formed at the point where the three rays intersect.
an image formed with the actual rays of light.
A real image
is an image formed from imaginary extensions of these rays of light
virtual image
_ are lenses that thin at the middle and bulk at the edges.
Diverging lenses
These are also known as _.
Diverging lenses
concave lenses
There are different kinds of diverging lenses, the most common is the _ _.
biconcave lens
Diverging lenses deflect _ rays away from each other, making it appear as if
they diverge from the focal point
parallel
The first ray is parallel to the principal axis of the diverging lens which will refract through the lens and travel in line with the focal point. This is known as the principal ray.
The second ray, the focal ray, passes towards the focus at the opposite side and will refract through the lens and travel parallel to the principal axis.
The third ray passes through the center of the lens is unrefracted, this is the central ray. It directly passes through the center without being bent.
The intersection of the extensions of the rays determines the location and characteristics of the image formed by the diverging lens.
distance of the object from the lens
(object distance)
(object distance)
d(o)
distance of the image from the lens
(image distance)
(image distance)
di
focal length
f
Lens Equation
1/f=1/do+1/di
M=hi/ho=-(di/do)
