In a double-slit experiment, two slits are 0.2 mm apart with a screen at a distance of 1m. The third bright fringe is found to be displaced at a distance of 7.5 mm from the central fringe. What is the value of the wavelength?
Correct answer: D. 0.0005 mm
- A. 0.03 mm
- B. 0.004 mm
- C. 0.00006 mm
- D. 0.0005 mm
Explanation
The explanation is given below:In the double slit experiment, the position of bright fringes is given by the equation:y = (mλD)/dWhere y is the displacement of the bright fringe from the central fringe, m is the order of the bright fringe, λ is the wavelength of light used, D is the distance from the slits to the screen, and d is the distance between the slits.In this problem, m = 3, d = 0.2 mm, D = 1 m, and y = 7.5 mm. Substituting these values into the above equation, we get:(3λ)/0.2 = 7.5/1000λ = (7.5/1000) x 0.2/3 = 0.0005 mmTherefore, the value of the wavelength is 0.0005 mm.
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About Superposition and Interference
Superposition states that overlapping waves produce a resultant displacement equal to the algebraic sum of their individual displacements. Interference covers constructive and destructive interference, phase difference, path difference, coherent sources, and conditions for maxima and minima. It differs from diffraction, which involves spreading around openings or obstacles.
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