interference

    Cards (33)

    • longitudinal wave
      particles of the material vibrate parallel as the motion of the wave
    • example of longitudinal wave
      sound
    • transverse waves
      the particles of the material vibrate perpendicular to the direction the wave is travelling
    • example of transverse waves
      light
    • frequency
      number of waves to pass a point in one second
    • period
      the time it takes for one wave to pass a point
    • in order for waves to interact with each other they must have the same frequency and wavelength
    • when two waves meet, they combine to produce an interference pattern
    • coherence
      same wavelength
      same frequency
      fixed phase difference
      same velocity
    • phase
      a measure of how "in step" waves are
    • if phase difference is zero
      waves are coherent
    • constructive interference
      waves meet crest to crest and trough to trough.
      are in phase
    • destructive interference
      waves meet crest to trough and are 180 degrees out of phase
    • what happens at constructive interference
      produce a larger crest
    • what happens at destructive interference
      produce no wave at that point
    • the difference in distance is known as the path difference
    • bright fringe
      constructive interference
    • dark fringe
      destructive interference
    • maxima
      constructive interference
    • minima
      destructive interference
    • the central maximum has zero path difference
    • increasing number of slits
      increases the distance between maxima
    • increasing distance to the screen
      increases the distance between maxima
    • increasing the wavelength
      increases the distance between maxima
    • wavelength of red light

      700 nm
    • wavelength of green light

      550 nm
    • wavelength of blue light

      500 nm
    • wavelength of violet light

      400 nm
    • prism
      only one spectrum produced
      red deviated least
      violet deviated most
      less widely spaced
    • grating
      many spectra produced
      red deviated most
      violet deviated least
      less intense
      more spread out
      central image same colour as the source
    • why is light from a grating less intense
      energy divided between several spectra
    • the name given to the spreading of light is known as diffraction
    • When light passes through a grating the wavefronts on the opposite side overlap resulting in a pattern being formed. The name given to this patterned phenomenon is:
      interference