Advertisements
Advertisements
प्रश्न
Compare Young’s Double Slit Interference Pattern and Single Slit Diffraction Pattern.
उत्तर
| Young’s double-slit interference pattern: | The single slit diffraction pattern | |
| i. | Dimension of slit: For a common laboratory setup, the slits in Young’s double-slit experiment are much thinner than their separation. They are usually obtained by using a biprism or a Lloyd’s mirror. The separation between the slits is a few mm only. | Dimension of slit: The single slit used to obtain the diffraction pattern is usually of width less than 1 mm. |
| ii. | Size of the pattern obtained: With the best possible setup, the observer can usually see about 30 to 40 equally spaced bright and dark fringes of nearly the same brightness. | Size of the pattern obtained: Taken on either side, the observer can see around 20 to 30 fringes with the central fringe being the brightest. |
| iii. | Fringe width W: W = `(λ "D")/"d"` | Fringe width W: W = `(λ "D")/"a"` Except for the central bright fringe |
| iv. | For nth bright fringe | |
| a. | Phase difference, Φ between extreme rays: n(2π) | Phase difference, Φ between extreme rays: `("n" + 1/2)` (2π) OR (2n + 1)π |
| b. | Angular position, θ: n`(λ/"d")` | Angular position, θ: `("n" + 1/2)(λ/"a")` OR `((2"n" + 1)λ)/(2"a")` |
| c. | Path difference, ∆l between extreme rays: nλ | Path difference, ∆l between extreme rays: nλ |
| d. | Distance from the central bright spot, y: n`((λ"D")/"d")` = nW | Distance from the central bright spot, y: `("n" + 1/2)((λ"D")/"a") = ("n" + 1/2)`W |
| v. | For nth dark fringe | |
| a. | Phase difference, Φ between extreme rays: `("n" - 1/2) (2pi)` OR (2n - 1)π | Phase difference, Φ between extreme rays: n(2π) |
| b. | Angular position, θ: `("n" - 1/2)(λ/"d")` OR (2n - 1)`λ/(2"d")` | Angular position, θ: n`(λ/"a")` |
| c. | Path difference, ∆l between extreme rays: `("n" - 1/2)λ` OR `(2"n" - 1)λ/2` | Path difference, ∆l between extreme rays: nλ |
| d. | Distance from the central bright spot, y': `("n" - 1/2)((λ "D")/"d") = ("n" - 1/2)`W | Distance from the central bright spot, y': n`((λ"D")/"a")` = nW |
APPEARS IN
संबंधित प्रश्न
In a biprism experiment, the fringes are observed in the focal plane of the eyepiece at a distance of 1.2 m from the slits. The distance between the central bright and the 20th bright band is 0.4 cm. When a convex lens is placed between the biprism and the eyepiece, 90 cm from the eyepiece, the distance between the two virtual magnified images is found to be 0.9 cm. Determine the wavelength of light used.
A star is emitting light at the wavelength of 5000 Å. Determine the limit of resolution of a telescope having an objective of a diameter of 200 inch.
What should be the slit width to obtain pronounced diffraction with a single slit illuminated by the light of wavelength λ?
What must be the ratio of the slit width to the wavelength for a single slit, to have the first diffraction minimum at 45˚?
What is the difference between Fresnel and Fraunhofer diffraction?
Explain Fraunhofer diffraction at a single slit with a neat ray diagram. Obtain an expression for the width of the central bright fringe.
In biprism experiment, the distance between source and eyepiece is 1.2 m, the distance between two virtual sources is 0.84 mm. Then the wavelength of light used if eyepiece is to be moved transversely through a distance of 2.799 cm to shift 30 fringes is ______.
Light of wavelength 'λ' is incident on a single slit of width 'a' and the distance between slit and screen is 'D'. In diffraction pattern, if slit width is equal to the width of the central maximum then 'D' is equal to ______.
For Fraunhofer diffraction to occur ____________.
In a single slit diffraction pattern, which of the following is incorrect for fringe pattern?
The angular spread of central maximum, in diffraction pattern, does not depend on ______.
A slit of width 'a' illuminated by white light. The first diffraction minimum for light of wavelength 6500 Å is formed at θ = 30°, then 'a' is (sin 30° = 0.5).
The condition for observing Fraunhofer diffraction pattern from an obstacle is that the light wavefront incident on it must be ______.
The diffraction fringes obtained by a single slit are of ____________.
Select the CORRECT statement from the following.
A parallel beam of monochromatic light falls normally on a single narrow slit. The angular width of the central maximum in the resulting diffraction pattern ______
When two coherent sources in Young's experiment are far apart, then interference pattern ______
A parallel beam of monochromatic light of wavelength 5 × 10-7 m is incident normally on a single narrow slit of width 10-3 mm. At what angle of diffraction, the first minima are observed?
In young 's double slit experiment the two coherent sources have different amplitudes. If the ratio of maximum intensity to minimum intensity is 16 : 1, then the ratio of amplitudes of the two source will be _______.
In Young's double slit experiment, the fringe width is 12 mm. If the entire arrangement is placed in water of refractive index `4/3`, then the fringe width becomes (in mm) ______.
The increase in energy of a metal bar of length 'L' and cross-sectional area 'A' when compressed with a load 'M' along its length is ______.
(Y = Young's modulus of the material of metal bar)
In Fraunhofer diffraction pattern, slit width is 0.2 mm and screen is at 2 m away from the lens. If wavelength of light used is 5000 Å, then the distance between the first minimum on either side of the central maximum is ______. (θ is small and measured in radian)
The angular separation of the central maximum in the Fraunhofer diffraction pattern is measured. The slit is illuminated by the light of wavelength 6000 Å. If the slit is illuminated by light of another wavelength, the angular separation decreases by 30%. The wavelength of light used is ______.
In Young's double slit experiment, the 8th maximum with wavelength λ1 is at a distance d1 from the central maximum and the 6th maximum with a wavelength λ2 is at a distance d2. Then d1/d2 is equal to ______.
The angular width of the central maximum of the diffraction pattern in a single slit (of width a) experiment, with λ as the wavelength of light, is ______.
In Young's double slit experiment using monochromatic light of wavelength λ, the maximum intensity of light at a point on the screen is K units. The intensity of light at point where the path difference is `lambda/3` is ______.
`[cos60^circ = sin30^circ 1/2]`
The first diffraction minimum due to single slit diffraction is θ, for a light wavelength 5000 Å. If the width of slit is 1 × 10-4 cm, then the value of θ is ______.
State the characteristics of a single slit diffraction pattern.
