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प्रश्न
What is the effect on the interference fringes to a Young’s double slit experiment when
(i) the separation between the two slits is decreased?
(ii) the width of a source slit is increased?
(iii) the monochromatic source is replaced by a source of white light?
Justify your answer in each case.
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उत्तर
(i) From the fringe width expression,
`beta =(lambdaD)/d`
With the decrease in separation between two slits, ‘d’ the fringe width increases.
(ii) For interference fringes to be seen
`s/S<lambda/d,`condition should be satisfied
Where, s = size of the source,
S = distance of the source from the plane of two slits.
As the source slit width increase, fringe pattern gets less and less sharp.
When the source slit is so wide the above condition does not satisfied and the interference pattern disappears.
(iii) The interference pattern due to different colour component of white light overlap. The central bright fringes for different colours are at the same position. Therefore central fringes are white. And on the either side of the central whit fringe coloured bands will appear.
The fringe closed on either side of central white fringe is red and the farthest will be blue. After a few fringes, no clear fringe pattern is seen.
संबंधित प्रश्न
Find the angular separation between the consecutive bright fringes in a Young's double slit experiment with blue-green light of wavelength 500 nm. The separation between the slits is \[2 \cdot 0 \times {10}^{- 3}m.\]
Consider the arrangement shown in the figure. The distance D is large compared to the separation d between the slits.
- Find the minimum value of d so that there is a dark fringe at O.
- Suppose d has this value. Find the distance x at which the next bright fringe is formed.
- Find the fringe-width.
In a Young's double slit interference experiment, the fringe pattern is observed on a screen placed at a distance D from the slits. The slits are separated by a distance d and are illuminated by monochromatic light of wavelength \[\lambda.\] Find the distance from the central point where the intensity falls to (a) half the maximum, (b) one-fourth the maximum.
A projectile can have the same range R for two angles of projection. If t1 and t2 be the times of flight in two cases, then what is the product of two times of flight?
Young's double slit experiment is made in a liquid. The 10th bright fringe lies in liquid where 6th dark fringe lies in vacuum. The refractive index of the liquid is approximately
Why is the diffraction of sound waves more evident in daily experience than that of light wave?
In a Young’s double slit experiment, the path difference at a certain point on the screen between two interfering waves is `1/8`th of the wavelength. The ratio of intensity at this point to that at the centre of a bright fringe is close to ______.
How will the interference pattern in Young's double-slit experiment be affected if the screen is moved away from the plane of the slits?
Monochromatic green light of wavelength 5 × 10-7 m illuminates a pair of slits 1 mm apart. The separation of bright lines in the interference pattern formed on a screen 2 m away is ______.
- Assertion (A): In Young's double slit experiment all fringes are of equal width.
- Reason (R): The fringe width depends upon the wavelength of light (λ) used, the distance of the screen from the plane of slits (D) and slits separation (d).
