Diffraction of sound wave

Lesson 16 of 21 • 2 upvotes • 10:31mins

Rajesh Kumar

Diffraction property of sound wave. Bending of sound wave. Wave spread in medium or in space when wave created by vibrating source if medium is homogenous and isotropic then wavefront of point source is spherical wave, at long distance this wavefront became plane wave. shape of wave change when meets an obstacle or opening in its path bending of the wave around the edge from an obstacle or an opening is called diffraction . when plane wavefront passed through a pinhole then it becomes a spherical wavefront and pinhole behave like point source. diffraction is a characteristic property of wave motion and all kinds of waves exhibit diffraction. condition: dimension of obstacle opening comparable or smaller than the wavelength of the wave, d less than or equal to wavelength. If d >wavelength diffraction effects are almost negligible if dimension of the opening obstacle greater than the wavelength of the wave. Frequency of the audible sound range 20Hz to 20 kilohertz, speed of sound in air 332 m per second then wavelength of audible sound greater than 1.6 cm and less than 16 m. for audible sound normally obstacles are opening have small dimensions so d diffractions normally observed for daily life for sound wave. Wavelength of light less than sound wave, so diffraction is more in longer wavelength .so diffraction easily observe in sound wave. sound wave travel around corners this is example of diffraction.