1Everything Science www.everythingscience.co.za6. 2D and 3D wavefrontsPhysicsGrade 11
2Everything Science www.everythingscience.co.zaWavefrontsA wavefront is an imaginary line that connects waves that are in phase.
3Everything Science www.everythingscience.co.zaHuygens principleHuygen’s Principle states thatevery point of a wave front servesas a point source of spherical,secondary waves. After a time t,the new position of the wave frontwill be that of a surface tangent tothe secondary waves.
4Everything Science www.everythingscience.co.zaDiffractionDiffraction is the ability of a wave to spread out in wavefronts as the wave passes through asmall aperture or around a sharp edge.
5Everything Science www.everythingscience.co.zaDiffraction through a slitWhen a wave passes through a slit, diffraction of the wave occurs. Diffraction of the wave iswhen the wavefront spreads out or “bends” around corners.
6Everything Science www.everythingscience.co.zaDiffraction through a slit continued...The degree of diffraction depends on the width of the slit and the wavelength (λ) of the wavewith diffraction proportional to the width of the slit (w).● Big slits (large w) have very little diffraction.● Small slits (small w) have a large diffraction.● Large wavelengths give large diffraction.● Small wavelengths give very little diffraction.diffraction∝ λw
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