Chapter 8- Light And Optics Flashcards
Visible light spectrum
400nm to 700nm
Electromagnetic waves
Transverse waves oscillating with electric and magnetic fields that are perpendicular to each other
Rectilinear propagation
When light travels through homogeneous mixture it travels in a straight line
Reflection
Rebounding of incident light waves at the boundary of a medium (bounce off)
Type of image for plane mirrors
Always virtual because light is in front but image looks like it’s behind the mirror
Convex mirror
Everything appears smaller and further away. Diverging.
Concave mirror
Everything appears bigger and closer. Converging.
Focal point for spherical mirrors
f = r/2
Mirror equation
1/f = 1/o + 1/i = 2/r
Image distance
Positive distance = real (in front of mirror)
Negative distance = virtual (behind mirror)
Magnification
-i/o
Refraction
Bending of light as it passes from one medium to another and changes speed
Speed of light in any medium besides a vacuum
It’s always less.
Index of refraction
n = c/v
n- index of refraction of the medium
Always larger than 1 for anything besides air.
Critical angle
sin -1 (n2/n1)
Total internal reflection
A phenomena in which all the light incident on a boundary is reflected back into the original material. When angle of incidence is greater than the critical angle
Lensmaker equation
1/f = (n-1) (1/r1 - 1/r2)
Positive focal length and radii of curvature for mirror and lens
Converging
Diverging lens or diverging mirror
Negative focal length and radii of curvature
Power of lens
P = 1/f
f- focal length in meters
Nearsighted vs farsighted lenses
Near- diverging lens
Far- converging lens
Hyperopia
Farsightedness
Myopia
Nearsightedness
Spherical aberration
Blurring of periphery of an image as a result of inadequate reflection of parallel beams at the edge of a mirror or inadequate refraction of parallel beams at the edge of a lens.
Location of dark fringes for single slit diffraction
a sin() = n(wavelength)
a- width of a slit
Positions of dark fringes with two slits
d sin() = (n + 1/2)(wavelength)
d- distance between two slits
Speed of light equation
c = f(wavelength)
For single mirrors or lenses
All real images are inverted
As light rays travel from one medium to another what changes
Wavelength only
If a ray of light is traveling from one medium to another where it’s going from a low index of refraction to a higher one then what happens to the angle?
It gets smaller
