SAT II Subject Test Physics: Geometrical Optics - Common applications

• Sight Correction Lenses
  
  1. Nearsighted people need to wear concave lenses because for them the image of an object is brought into focus too soon (in front of the retina)
     
  2. farsighted people need to wear convex lenses because for them the image of an object is brought into focus beyond the retina.
     
  
• Understand lens f-numbers
f/8 means the diameter of the lens is 1/8 of the focal point
• Understand the principle of astronomical telescope and compound microscope
  
  1. Telescope magnification =
     (focal length of the object)/(focal length of the eyepiece)
     
  2. Microscope magnification =
     (power of eyepiece) x (power of object piece)
     
• What is monochromatic light
The light that has one single color
• What is chromatic aberration
The focal length of a lens varies upon the color of light.
• Fraunhofer lines in Sun's spectrum are produced mostly by the gases in Sun's atmosphere that absorb some of the energy emitted from the hot core