Geometrical optics Flashcards
What is the reflected angle for a light ray that contacts water at an angle 30 degrees to the normal?
30 degrees (law of reflection states that the angle of incoming light ray is equal and opposite the outgoing light ray)
Where is the image created in a plane mirror?
equal distance behind the mirror to the distance between the object and the mirror. This is a virtual image.
What constitutes a real image?
the image converges with the object
What is a converging mirror and how does it deflect light rays?
Converging mirror is like looking into a cave or at the dipped side of a spoon. It deflects light rays come together at a central point
What is a diverging mirror and how does it deflect light rays?
diverging mirror is like looking at the back side of a spoon. It deflects light rays so that they all split apart.
What is the focal length of a spherical mirror?
one half of the radius of the sphere. f=r/2
How are focal length, image location, and object location related in a spherical mirror?
1/f=1/o+1/i=2/r
o=object position from mirror
i=image position from mirror
Concerning image distance from a spherical mirror, when is the image real or virtual?
real if i>0 (in front of the mirror or on same side as the object), virtual if i
What is magnification?
the negative ratio of the image distance to the object distance.
M = -i/o
What happens to the image when the object is at the focal point? when it is inside the focal point? (concave mirror)
no image - rays do not converge
virtual image - rays must be drawn behind mirror
An object in any location in front of a convex mirror will produce what kind of image?
virtual, reduced, upright
What is the index of refraction?
n=c/v = speed of light in a vacuum/speed of light in medium, n=1 in a vacuum n>1 in any medium
In which direction does light bend when traveling from medium with a higher n to a lower n? what law is used?
snells law - light bends away from the normal if n1>n2
when does total internal reflection occur?
when the incident angle is greater than the critical angle
difference between converging and diverging lenses?
converging are convex and cause parallel light rays to converge/come together, diverging (concave) lenses cause parallel light rays to divert/split apart.
Light is refracted twice (through air and lens)
