Interference Physics Example 2

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Example 2

medium
In a double-slit experiment, light of wavelength 500 nm500 \text{ nm} passes through slits 0.2 mm0.2 \text{ mm} apart. A screen is 2 m2 \text{ m} away. What is the spacing between adjacent bright fringes?

Solution

  1. 1
    Fringe spacing formula: Δy=λDd\Delta y = \frac{\lambda D}{d}, where DD is screen distance and dd is slit separation.
  2. 2
    Δy=500×10−9×20.2×10−3=10−62×10−4\Delta y = \frac{500 \times 10^{-9} \times 2}{0.2 \times 10^{-3}} = \frac{10^{-6}}{2 \times 10^{-4}}
  3. 3
    Δy=5×10−3 m=5 mm\Delta y = 5 \times 10^{-3} \text{ m} = 5 \text{ mm}

Answer

Δy=5 mm\Delta y = 5 \text{ mm}
Young's double-slit experiment demonstrates wave interference. The fringe spacing increases with wavelength and screen distance, and decreases with slit separation. This experiment provided key evidence that light behaves as a wave.

About Interference

The phenomenon that occurs when two or more waves overlap in space, combining their displacements at every point according to the principle of superposition.

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More Interference Examples

Example 1 easy

Two speakers emit identical sound waves in phase. A listener stands equidistant from both speakers.

Example 3 medium

Two coherent light sources create an interference pattern. The third bright fringe is observed at an

Example 4 hard

In a double-slit experiment, the slit separation is [formula] and the screen is [formula] away. If t

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