Diffraction
- Diffraction is the spreading of a wave when it travels through an opening or a small obstacle.
(Diffraction happen when waves pass through an opening) |
(Diffraction happen when waves encounter an obstacle)
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- Characteristics of Diffracted Wave
- Wavelength does not change.
- Frequency does not change.
- Speed of diffracted does not change.
- The amplitude of the wave decreases after diffraction.
Factors Affecting the Magnitude of Diffraction
The magnitude of diffraction (or angle of diffraction) depends on
- The wavelength
- The size of the opening
Experiment 1
Shorter wavelength – The wave spreads to a smaller area
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Longer wavelength – The wave spreads to a wider area
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Conclusion:
Diffraction is affected by the wavelength. The longer the wavelength, the greater the effect of diffraction |
Experiment 2
Bigger opening – The wave spreads to a smaller area
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Smaller opening – The wave spreads to a wider area
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Conclusion:
Diffraction is affected by the size of the opening. The smaller the size of the opening, the greater the effect of diffraction |