Physics Exam 3 Flashcards
convex spherical mirror
has a reflecting surface that bulges outward
-reflects rays that are parallel to its principal axis so they diverge
spherical mirror
has a spherical reflecting surface
concave spherical mirror
has a hollowed reflecting surface
-reflects rays that are parallel to its principal axis so that they pass through a point known as the focal point
focal length
distance from the surface of the mirror to the focal point
paraxial rays
rays that are rays that are close to the principal axis of a mirror
spherical aberration
blurred effect caused from rays that are farther from the axis
mirror equation
relates the object distance, image distance, and focal length
*focal length is positive for a concave mirror and negative for convex
human eye
forms a real, but inverted, image on the retina
camera
forms a real, but inverted, image on light-sensitive material
focusing the eye
- focused by the ciliary muscles, which change the shape of the lens
- process is known as accommodation
focusing a camera
- focused by moving the lens closer to or farther away from the light-sensitive material
- shape of the lens is unchanged
near point
- the closest distance to which the eye can focus
- typical value is 25cm
far point
- the greatest distance at which the eye can focus
- far point is infinity
f-number
relates the diameter of the aperture to the focal length
nearsightedness
a condition in which clear vision is restricted to a region relativly close to the eye
- the far poinr is nor infinity
- can be corrected with diverging lenses placed in front of eyes
farsightedness
- person can see clearly only at a relatively large distance from the eye
- the person’s near point is much farther from the eye
- can be corrected by placing converging lenses in front of the eyes
refractive power of a lens
refers to its ability to bend light and is measured in diopters
- the greater the magnitude of the refractive power, the more strongly the lens bends light
- a positive refractive power indicates a converging lens
- a negative refractive power indicates a diverging lens
magnifying glass
- a converging lens
- works by allowing an object to be viewed at a distance less than the near-point distance
compound microscope
uses two lenses in combination to produce a magnified image
- an objective 2. eyepiece
- object to be viewed is placed just outside the focal length of the objective
- image formed by the objective lens is viewed by the eyepiece giving additional magnification
telescope
provides magnified views of distant objects using two lenses
- the objective lens focuses the incoming light at its focal point
- the eyepiece magnifies the image formed by the object
length of a telescope
the sum of the focal lengths of its two lenses
reflecting telescope
uses a mirror in pace of an objective lens
-the largest telescopes are reflectors
lens aberration
any deviation of a lens from ideal behavior
spherical aberration
parallel rays of light passing through a lens fail to go through a single focal point
-its related to the shape of a lens
chromatic aberration
results from dispersion withon a refracting material
-causes different colors to focus at different points
superposition
the addition of two or more waves to give a resultant wave
superposed waves
the result may be a wave of greater amplitude (constructive interference)
-or reduced ampliture (destructive interference)
monochromatic light
consists of waves with a single frequency and a single color