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E. Wave Nature of Light
2 Competing Theories :
Behavior of Light Supporting Wave Theory
1. Diffraction – light spreads out into the region behind an obstacle
2. Interference – Young’s Double Slit Late 1800's
λ/d = x/L - St. Mary's Physics
Monochromatic Coherent Which light source is coherent?
June 1997 Regents Test Double Slit - Wavelength Difference- Michael Fowler Flashlets
If you draw a line from each slit to the 1st order bright line, you will notice that one line is longer than the other.
The difference between these two lines is 1λ. Destructive interference - 1/2, 1 1/2, 2 1/2 ... Wavelength difference
Constructive Interference causes ..
Bright Lines
Destructive Interference causes...
Dark Lines
Ex) Calculate the distance between two slits in a Double Slit Experiment if the wavelength of the light used is is 5 x 10-7 m and the distance between the central maximum and the first order bright line is 2 x 10-2 m. The distance from the slits to the screen is 4 meters.
Question: If they give you d, L and x and asked you to find the COLOR of the
light used, What would you do? Where would you go to find the color? 1. Solve for λ use Young's Equation 2. Use 3 x 108 m/s = fλ to find the colors frequency 3. Look up the color on page 2 Ref.
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