Optics

• Rainbow


  Result of dispersion, Intruction, reflection of light
• Polarization


  Characteristic of all transverse waves
• Incident ray


  Ray of light that falls on the refracting surface
• Reflecting ray


  Ray of light that is sent back by the reflecting surface
• Angle of incidence


  Angle made by the incident ray and the normal
• Angle of reflection


  Angle made by the reflected ray and the normal
• Object


  Forms an image on the screen
• Image


  Reflection of the object on the screen
• Thermal radiation


  Electromagnetic radiation as a result of thermal motion of particles
• Light


  Produced during electrical discharges through ionized gases
• Speed of light in vacuum

  C = 3x10^8 m/s
• Ray


  Imaginary line to describe the directions, which light propagates
• Plane wave


  Reflected and in part refracted at the boundary between two media
• Specular reflection


  Reflection at a definite angle, very smooth surface
• Diffuse reflection


  Scattered reflection from a rough surface
• Dispersion of light by a prism

  The colors is called spectrum
• Virtual image


  Cannot be obtained on a screen
• Real image


  Formed directly on the screen
• Concave mirror


  Curved inward
• Convex mirror


  Curved outward
• Focus of a concave mirror


  On the principle axis, all the rays parallel to the principle axis converge
• Focus of a convex mirror


  Point on the principle axis, the reflected rays appear to converge
• Focal length of Spherical Mirrors


  Distance between the pole and principal focus
• Optical focus


  Center point of a lens
• Principal axis


  Line passing through the optical center
• Focus


  The point when rays converge after refraction
• Plane of Incident 


  the plane where the incident, reflected and refracted rays and the normal to the surface all lie
• 1.0003


  It is the value of the index of refraction of air at standard temperature and pressure
• Dispersion 


  It is the dependence of the refraction index on the wavelength
• Unpolarized light 


  Random mixture of wave polarized in all transverse directions
• Normal 


  a line at right angle to the reflecting surface to the point of incidence