Advertisements
Advertisements
Question
The intensity of the light coming from one of the slits in Young's experiment is twice the intensity of the light coming from the other slit. What will be the approximate ratio of the intensities of the bright and dark fringes in the resulting interference pattern?
Advertisements
Solution
Data: I1 : I2 = 2 : 1
If E10 and E20 are the amplitudes of the interfering waves, the ratio of the maximum intensity to the minimum intensity in the fringe system is
`("I"_"max")/("I"_"min") = (("E"_10 + "E"_20)/("E"_10 - "E"_20))^2 = (("r + 1")/("r - 1"))^2`
where r = `"E"_10/"E"_20`
∴ `"I"_1/"I"_2 = (("E"_10)/("E"_20))^2 = "r"^2`
∴ r = `sqrt("I"_1/"I"_2) = sqrt2`
∴ `("I"_"max")/("I"_"min") = ((sqrt2 + 1)/(sqrt2 - 1))^2 = (2.414/0.414)^2 = (5.83)^2`
= 33.99 ≈ 34.
∴ The ratio of the intensities of the bright and dark fringes in the resulting interference pattern is 34: 1.
APPEARS IN
RELATED QUESTIONS
Answer in brief:
In Young's double-slit experiment what will we observe on the screen when white light is incident on the slits but one slit is covered with a red filter and the other with a violet filter? Give reasons for your answer.
What are the two methods for obtaining coherent sources in the laboratory?
A double-slit arrangement produces interference fringes for sodium light (λ = 589 nm) that are 0.20° apart. What is the angular fringe separation if the entire arrangement is immersed in water (n = 1.33)?
Why two light sources must be of equal intensity to obtain a well-defined interference pattern?
One of Young’s double slits is covered with a glass plate as shown in figure. The position of central maximum will,
Obtain the equation for bandwidth in Young’s double slit experiment.
Discuss the interference in thin films and obtain the equations for constructive and destructive interference for transmitted and reflected light.
Does diffraction take place at Young’s double-slit?
In Young’s double-slit experiment, 62 fringes are seen in the visible region for sodium light of wavelength 5893 Å. If violet light of wavelength 4359 Å is used in place of sodium light, then what is the number of fringes seen?
The ratio of maximum and minimum intensities in an interference pattern is 36 : 1. What is the ratio of the amplitudes of the two interfering waves?
Light of wavelength 600 nm that falls on a pair of slits producing interference pattern on a screen in which the bright fringes are separated by 7.2 mm. What must be the wavelength of another light which produces bright fringes separated by 8.1 mm with the same apparatus?
If the monochromatic source in Young's double slit experiment is white light, then ____________.
A thin transparent sheet is placed in front of a slit in Young's double slit experiment. The fringe width will ____________.
In Young's experiment for the interference of light, the separation between the silts is d and the distance of the screen from the slits is D. If D is increased by 0.6% and d is decreased by 0.2%, then for the light of a given wavelength, which one of the following is true?
"The fringe width ____________."
A thin mica sheet of thickness 4 x 10-6 m and refractive index 1.5 is introduced in the path of the first wave. The wavelength of the wave used is 5000 A. The central bright maximum will shift ______.
In Young's double slit experiment with a source of light of wavelength 5860 Å, the first maxima will occur when ____________.
In Young's double slit experiment the source is white light. One slit is covered with red filter and the other with blue filter. There shall be ____________.
In a biprism experiment, red light of wavelength 6500 Å was used. It was then replaced by green light of wavelength 5200 Å. The value of n for which (n + 1)th green bright band would coincide with nth red bright band for the same setting is ______.
In the Young's double slit experiment, if the phase difference between the two waves interfering at a point is `phi`, the intensity at that point is proportional to ____________.
If two waves represented by `"y"_1 = 3 "sin" omega "t"` and `"y"_2 = 5 "sin" (omega "t" + pi/3)` interfere at a point, then the amplitude of the resulting wave will be about ____________.
Two identical light sources s1 and s2 emit light of same wavelength `lambda`. These light rays will exhibit interference if their ______.
In biprism experiment, if the 5th bright band with wavelength 'λ1' coincides with the 6th dark band with wavelength 'λ2' then the ratio `(lambda_2/lambda_1)` is ______
Waves from two coherent sources of light having an intensity ratio I1 : I2 equal to 'x' interfere. Then in the interference pattern obtained on the screen, the value of (Imax - Imin)/(Imax + Imin) is ______
In a biprism experiment, monochromatic light of wavelength (λ) is used. The distance between two coherent sources is kept constant. If the distance between slit and eyepiece (D) is varied as D1, D2, D3, and D4, the corresponding measured fringe widths are z1, z2, z3, and z4 then ______
Two waves with same amplitude and frequency superpose at a point. The ratio of resultant intensities when they arrive in phase to that when they arrive 90° out of phase is ______.
`[cos pi/2=0]`
What is meant by Constructive interference?
A beam of electrons is used in Young's double-slit experiment. If the speed of electrons is increased then the fringe width will ______.
How will the interference pattern of Young's double slit change if one of the two slits is covered by a paper which transmits only half of the light intensity?
