Kaplan Physics - Chapter 8: Light and Optics
Terms in this set (40)
Transverse waves that consist of an oscillating electric field and an oscillating magnetic field.
1) The two fields are perpendicular to each other and to the direction of propagation of the wave.
Range of frequencies and wavelengths found in EM waves. Highest: Radio
Electromagnetic spectrum mnemonic
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(low) Gamma xray ultraviolet infared micro radio (High)
Visible light spectrum
Runs from approximately 400 nm (violet) to 700 nm (red)
Highest ROY G BV Lowest
Speed of light from frequency and wavelength equation:
c= 3.00 x 10^8
The rebounding of incident light waves at a boundary of a medium.
Law of reflection
States that the incident angle will be equal to the angle of reflection, as measured from the normal.
Center of curvature
The center of curvature would be the center of the spherically-shaped mirror if it were a complete sphere.
Concave mirrors look like a Cave!
1) Center of curvature/ radius located in front of mirror
2) Converging systems and can produce real, inverted images or virtual, upright images depending on the placement of the object to the focal point.
Convex mirrors = security mirror
1) Diverging systems
2) Forms ONLY virtual, upright, and reduced images
3) Focal point behind the mirror
Produce virtual, upright images: these images are always the same size as the object. They may be thought of as spherical mirror with infinite radii of curvature.
The distance between the focal point and the mirror. For all spherical mirrors, the focal point (f) = r/2
The distance from the mirror to the image.
1) If the image has a positive distance, it is in front of the mirror and real
2) If the image has a negative distance, it is behind the mirror and virtual
The distance from the mirror to the object
The dimensionless value that is a ratio of the image distance to object distance.
1) Negative magnification = inverted
2) Postive magnification = upright
3) [M] < 0 = reduced
4) [M] > 0 = larger
Sign conventions for a Single Mirror
the focal length of converging mirrors (and converging lenses) will always be positive
the focal length of diverging mirrors (and diverging lenses) will always be negative
Image types Mnemonic
UV (ultraviolet light) = Upright images always virtual
IR (infrared light) = Inverted images always real
Ray diagram points
any time an object is at the focal point of a converging mirror, the reflected rays will be parallel and the image will be at infinity
Optics problem example
Optics prob continued..
The bending of light as it passes from one medium to another.
1) Speed of light changes depending on the index of refraction in the medium. This speed change causes refraction.
Refraction: Bending toward or away from normal?
Lower n (air) to higher n (mud) = toward normal
Higher n (mud) to lower n (air) = away from normal.
Amount of refraction?
Dependent on the wavelength of the light involved; this behavior causes dispersion of light through a prism.
Snell's law (law of refraction)
States that there is an inverse relationship between the index of refraction and the sin angle of the refraction (measured from the normal).
Total internal refraction
Occurs when the light cannot be refracted out of the medium and is instead reflected back inside the medium.
1) This happens when light moves through the medium with a higher index of refraction to a medium with a lower index of refraction with a high incident angle.
2) minimum incident angle at which internal reflection occurs = critical angle
Refract light to form images of objects:
1) Concave lenses (diverging)
2) Convex lenses (converging)
have 2 focal points
Converging systems and can produce real, inverted images or virtual, upright images.
Diverging systems and will only produce virtual, upright images.
What type of lenses needed for "nearsightedness" and "farsightedness" ?
Nearsightedness = concave lenses
farsightedness = convex lenses
Sign conventions for lenses
lenses with non-negligible thicknesses
Multiple lens systems
lenses in contact are a series of lenses with negligible distances between them
m = m1 x m2 ...
The bending and spreading out of light waves as they pass through a narrow slit.
1) May produce a large central light fringe surrounded by alternating light and dark fringes with the addition of a lense
Interference in diffraction?
Supports the wave theory of light
Young's double slit experiment?
Shows the constructive and destructive interference of waves that occurs as light passes through parallel slits, resulting in minima (dark fringes) and maxima (bright fringes) of intensity.
All of the light rays have electric fields with a parallel oreintation
Circularly polarized light
All of the light rays have electric fields with equal intensity but constantly rotating direction
*created by exposing unpolarized light to special piglets or filters.