Interference in Thin Films and Waves

It will exhibit both constructive and destructive interference for different wavelengths.

Interference creates a lasting intensity pattern by allowing multiple waves to superpose in space.

Diffraction refers to the bending of waves around corners when wavefronts are obstructed.

<p>Huygens's principle states that each point on a wavefront acts as a point source that emits secondary wavelets.</p> Signup and view all the answers

<p>The colorful bands are formed due to the interference of light reflecting off different layers of the thin film.</p> Signup and view all the answers

<p>Constructive interference occurs when waves align in phase, boosting the amplitude of the resultant wave.</p> Signup and view all the answers

<p>Destructive interference occurs when waves are out of phase, reducing or canceling the amplitude of the resultant wave.</p> Signup and view all the answers

<p>Practical applications include creating anti-reflective coatings and enhancing optical devices.</p> Signup and view all the answers

<p>Destructive interference occurs when the path-length difference is zero or a whole number of wavelengths.</p> Signup and view all the answers

<p>It undergoes a 180° phase change because the index of refraction of glass is greater than that of water.</p> Signup and view all the answers

<p>The thickness of the film affects the path-length difference, which in turn determines the spacing between bright and dark fringes.</p> Signup and view all the answers

<p>Newton's rings are circular interference fringes formed by light reflected from an air film between a spherical glass surface and a plane glass surface.</p> Signup and view all the answers

<p>Alternating bright and dark bands, known as interference fringes, are observed.</p> Signup and view all the answers

<p>This formula calculates the phase difference between two rays based on the path-length difference in the film.</p> Signup and view all the answers

<p>Constructive interference occurs when the path-length difference is an odd number of half-wavelengths.</p> Signup and view all the answers

<p>The index of refraction determines whether a 180° phase shift occurs upon reflection, affecting the resultant interference pattern.</p> Signup and view all the answers

<p>The intensity decreases to zero at an angle specified by $sin u_1 = \frac{\lambda}{a}$.</p> Signup and view all the answers

<p>Increasing the slit width 'a' results in a decrease in the angle $u_1$, leading to a narrower central diffraction maximum.</p> Signup and view all the answers

<p>For valid angles, the slit width 'a' must be greater than or equal to the wavelength 'λ'.</p> Signup and view all the answers

<p>This equation describes the relationship between the first zero intensity angle and the slit width and wavelength.</p> Signup and view all the answers

<p>Reducing the slit width 'a' increases the angle $u_1$, resulting in a broader central diffraction maximum.</p> Signup and view all the answers

<p>When 'a' is smaller than 'λ', there are no points of zero intensity, and the slit acts as a line source radiating light uniformly.</p> Signup and view all the answers

<p>The path-length difference for the light rays is given by $2a \sin u_1$.</p> Signup and view all the answers

<p>The major feature is the broad central diffraction maximum with minor secondary maxima on either side.</p> Signup and view all the answers

<p>The half-width $y_1$ is related to $u_1$ by the equation $y_1 = L an u_1$.</p> Signup and view all the answers

<p>This equation relates the angle $u_1$ to the slit width $a$, which is crucial for analyzing how light diffracts through the slit.</p> Signup and view all the answers

<p>In the small-angle approximation, $ ext{sin } u_1 ext{ is approximately equal to } an u_1$.</p> Signup and view all the answers

<p>The approximate value of $2y_1$ is about $4.2 imes 10^{-2}$ m or $4.2$ cm.</p> Signup and view all the answers

<p>The slit separation $d$ influences how the individual slit diffraction patterns combine, modulating the overall intensity on the screen.</p> Signup and view all the answers

<p>The intensity pattern with two slits appears as an interference pattern that is modified by the single-slit diffraction envelope.</p> Signup and view all the answers

<p>This relationship is valid as it indicates when the condition for diffraction occurs, specifically that the wavelength is less than the slit width.</p> Signup and view all the answers

<p>It implies that the intensity from each slit decreases with angle, leading to an overall intensity that is not constant but varies.</p> Signup and view all the answers

<p>The wavelength is 589 nm.</p> Signup and view all the answers

<p>The slit width affects the intensity pattern such that as the angle increases, the intensity on the screen decreases.</p> Signup and view all the answers

<p>The screen is 6.0 m away from the light source.</p> Signup and view all the answers

<p>Lloyd’s mirror was used to determine the location of distant radio sources by reflecting radio waves off the sea surface.</p> Signup and view all the answers

<p>Coherence is essential as it ensures that the two sources of light, the original and its reflection, maintain a constant phase relationship.</p> Signup and view all the answers

<p>When slits are not narrow, the intensity on the screen varies and decreases with increasing angle.</p> Signup and view all the answers

<p>Fringe spacing refers to the distance between two successive bright or dark interference fringes on the screen.</p> Signup and view all the answers

<p>The angle $u$ is important as it relates to the path difference and impacts the intensity observed at any point on the screen.</p> Signup and view all the answers

<p>Fraunhofer patterns occur at great distances or require lens focusing, while Fresnel patterns are observed close to the aperture or obstacle, where rays are not parallel.</p> Signup and view all the answers

<p>Fresnel demonstrated the existence of a bright spot at the center of the shadow cast by an opaque disk, countering Siméon Poisson's doubts about his wave theory.</p> Signup and view all the answers

<p>Fresnel diffraction is more complex because the rays are not parallel when considered near the aperture or obstacle, making calculations more difficult.</p> Signup and view all the answers

<p>The bright spot results from constructive interference of light waves diffracted from the edges of the disk.</p> Signup and view all the answers

<p>The diffraction patterns from a circular aperture and an opaque disk are complements of each other.</p> Signup and view all the answers

<p>Distance affects the diffraction pattern; closer distances produce Fresnel patterns, while farther distances produce Fraunhofer patterns.</p> Signup and view all the answers

<p>The pattern consists of alternating bright and dark regions due to the diffraction and interference of light waves.</p> Signup and view all the answers

<p>Diffraction patterns provide insights into the wave nature of light and the behavior of light waves as they interact with obstacles.</p> Signup and view all the answers