Any time that's the case, this rule holds in fact, this is the fundamental rule for almost all wave interference aspects. Where n = ±0,1,2,3….. Construct a sketch of the physical situation and determine the nodal line number. The phase difference is the difference in phase angle between two waves.
Soft reflection: Reflects off a medium with a lower refraction index, as a result, no phase shift is observed. Thin-film interference is the phenomenon that is a result of lightwave being reflected off two surfaces that are at a distance comparable to its wavelength. The refractive index of the thin soap film of uniform thickness is 1.4. Observe that the wave from Source 1 (S1) travels a distance of 3.5 wavelengths. It occurs mostly when light is reflected several times off (interference) the sides of thin transparent material. The 0th fringe represents the central bright fringe. In the next part of Lesson 3 we will investigate the nature of a two-point source light interference and make the connection between these simple ripple tank patterns and the observations made by Thomas Young when he first demonstrated two-point source light interference in the early 1800s. Or, ynth = nλ Dd. {{I}_{1}}\ne {{I}_{2}},{{I}_{\min }}\ne 0.I1=I2,Imin=0. The Young’s double slit experiment was a watershed moment in scientific history because it firmly established that light indeed behaved as a wave.
. Thus, there are two waves emerging from a thin film – one wave reflected off the top surface of the film and the other reflected off the bottom surface. So point P is 8 cm further from the farther source than it is from the nearer source.
From the geometry of the triangles AEB, AFB, ABC, and ACF, In triangle ACD, Sin i = AD / AC –––––– (i), In triangle AGC, Sin r = GC / AC –––––– (ii), Now, Path difference = µ (AB + BC) – AD = µ (AB + BC) – µGC = µ (AB + BC – GC), Path difference = µ (BF + BC – GC) [because AB=BF], FG = 2t cos r [because AF = AE +EF = t + t], where t is the thickness of the thin film. Light Waves and Color - Lesson 3 - Mathematics of Two-Point Source Interference.
And since the antinode lies on the third antinodal line, m = 3. The original Young’s double-slit experiment used diffracted light from a single source passed into two more slits to be used as coherent sources. In general, for best results, dD must be kept as small as possible for a good interference pattern. If I1≠I2,Imin≠0. For point A on the first antinodal line (m =1), the path difference is equivalent to 1 wavelength.
The optical path difference between the rays from the two coherent sources at point P on the screen is 0.0080 mm and at point Q on the screen is 0.0022 mm.