So, really, it is the difference in path length from each source to the observer that determines whether the interference is constructive or destructive. I emphasize this point, because it is true in all situations involving interference. In case of constructive interference, the value of ϕ =0 and so Cos ϕ =1.Then I R = I 1 + I 2 + 2 (√ I 1 I 2 = (√ I 1 + √ I 2) 2 where the waves are superposed in same phase. The key is to compare the number of wavelengths it takes for each light wave to travel from the slit to the wall.
These sources should be very close to each other.



What is the best description of the destructive interference of light? As laser light is diffracted through the two barrier slits, each diffracted wave meets the other in a series of steps, as illustrated in Figure 4 (and graphically in the interactive Java tutorial described above).
Regions of constructive interference, corresponding to bright fringes, are produced when the path difference from the two slits to the fringe is an integral number of wavelengths of the light. For white light incident on a film that varies in thickness, you will observe rainbow colors of constructive interference for various wavelengths as the thickness varies.

Thin film interference thus depends on film thickness, the wavelength of light, and the refractive indices. Other articles where Constructive interference is discussed: interference: …wave amplitudes are reinforced, producing constructive interference; but, if the two waves are out of phase by 1 2 period (i.e., one is minimum when the other is maximum), the result is destructive interference, producing complete annulment if they are of equal amplitude. Real-world interference phenomena are not as clearly defined as the simple case depicted in Figure 4.For example, the large spectrum of color exhibited by a soap bubble results from both constructive and destructive interference of light waves that vary in … 5.2 Constructive and Destructive Interference. Interference of Light Waves is defined as the modification in the distribution of light energy when two or more waves superimpose each other.

Encyclopædia Britannica, Inc. The light waves interfere when they have the same frequency , amplitude and phase producing regions of constructive interference and regions of destructive interference , They diffract in the same medium when they pass through a slit or by a sharp edge having dimensions near to the wavelength of the light waves.. Light interference. These sources should emit continuous waves of same wave length and same time period. The wave interference is said to be a constructive wave interference if the crest of a wave meets the crest of another wave of the same frequency at the same point. Interference of light waves supports the wave theory of light. Thin-film interference is a natural phenomenon in which light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.When the thickness of the film is an odd multiple of one quarter-wavelength of the light on it, the reflected waves from both surfaces interfere to cancel each other. As laser light is diffracted through the two barrier slits, each diffracted wave meets the other in a series of steps, as illustrated in Figure 4 (and graphically in the interactive Java tutorial described above). For destructive interference, the waves superpose in opposite direction.

A. a longitudinal wave meets transverse light wave B. two waves have the same direction of displacement C. a mechanical wave meets an electromagnetic wave D. two waves have displacement in opposite directions Interference of Light Waves. Constructive interference occurs when the maxima of two waves add together (the two waves are in phase), so that the amplitude of the resulting wave is equal to the sum of the individual amplitudes. The individual waves will add together (superposition) so that a new wavefront is created.

Here the resultant intensity is maximum. Principle of superposition of light wave When two or more light waves are travelling simultaneously through a medium or space, the resultant displacement at point and at a given time due to all the waves is given by the vector sum of the individual displacements produced by each wave separately at the same time. The only difficulty lies in properly applying this concept.