Interference of Light Waves and Young's Experiment

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Interference of Light Waves and Young's Experiment: Overview

This topic covers concepts, such as, Interference of Light Waves, Young's Double Slit Experiment, Condition for Sustained Interference & Condition for Good Contrast in Interference Pattern etc.

Important Questions on Interference of Light Waves and Young's Experiment

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How the angular separation of interference fringes in Young’s double slit experiment would change when the distance between the slits and screen is doubled?

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How the angular separation of interference fringes in Young’s double slit experiment would change when the distance between the slits and screen is doubled?

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In Young’s double-slit experiment, monochromic light of wavelength 630 nm illuminates the pair of slits and produces an interference pattern in which two consecutive bright fringes are separated by 8.1 mm. Another source of monochromic light produces the interference pattern in which the two consecutive bright fringes are separated by 7.2 mm. Find the wavelength of light from the second source.

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In Young’s double slit experiment, monochromic light of wavelength 600 nm illuminates the pair of slits and produces an interference pattern in which two consecutive bright fringes are separated by 10 mm. Another source of monochromic light produces the interference pattern in which the two consecutive bright fringes are separated by 8 mm. Find the wavelength of light from the second source.

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The effect on the interference fringes if the monochromatic source is replaced by a source of white light would be:

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How the angular separation of interference fringes in Young’s double slit experiment would change when the distance between the slits and screen is halved:

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In a Young’s double slit experiment, the two slits are kept 2 mm apart and the screen is positioned 140 cm away from the plane of the slits. The slits are illuminated with light of wavelength 600 nm.

(i) Find the distance of the third bright fringe from the central maximum in the interference pattern obtained on the screen.

(ii) If the wavelength of the incident light were changed to 480 nm, find out the shift in the position of third bright fringe from the central maximum.

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A parallel beam of monochromatic light falls normally on a single narrow slit. How does the angular width of the principal maximum in the resulting diffraction pattern varies with the width of the slit?

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How the fringe pattern changes when the screen is moved away from the slits:

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The way the fringe pattern changes when the screen is moved away from the slits is 

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In Young’s double slit experiment, the two slits 0.20 mm apart are illuminated by monochromatic light of wavelength 600 nm. The screen is 1.0 m away from the slits.

Find the distance of the second (i) bright fringe,
​(ii) dark fringe from the central maximum.

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In Young’s double-slit experiment, the two slits, 0.12 mm apart, are illuminated by monochromatic light of wavelength 420 nm. If the screen is 1.0 m away from the slits, then the distance of the second bright fringe from the central maximum is

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In Young’s double slit experiment, the two slits 0.15 mm apart are illuminated by monochromic light of wavelength 450 nm. The screen is 1.0 m away from the slits.

(a) Find the distance of the second (i) bright fringe, (ii) dark fringe from the central maximum.

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Which of the following expressions is/are correct for Young’s experiment?

(i) condition for bright fringes   x=nλ D d

(ii) condition for dark fringes   x=( 2n1 ) λ 2 D d

ii) fringe width   β= λD d

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Which of the following expressions is/are correct for Young’s experiment?

(i) condition for bright fringes   x=nλ D d

(ii) condition for dark fringes   x=( 2n1 ) λ 2 D d

ii) fringe width   β= λD d

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A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at a distance of 9 metres and 25 metres respectively from the source. The ratio of amplitudes of the waves at P and Q is ___________

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A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at a distance of 9 metres and 25 metres respectively from the source. The ratio of amplitudes of the waves at P and Q is ___________

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In a Young’s double slit experiment, 12 fringes are observed to be formed in a certain segment of the screen when light of wavelength 600 nm is used. If the wavelength of light is changed to 400 nm, number of fringes observed in the same segment of the screen is given by

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In a Young’s double slit experiment, 12 fringes are observed to be formed in a certain segment of the screen when the light of wavelength 600 nm is used. If the wavelength of light is changed to 400 nm, number of fringes observed in the same segment of the screen is given by

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Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is   π 2  at point A and   π at point B. Then the difference between the resultant intensities at A and B is