A double-slit interference experimented in this illustration: I. II. 0.4 mm 2 m Y viewing screen If the order bright fringe falls to 12mm from the center of the pattern, what is the wavelength of the light used? A glass with n=1.55, is inserted between the slits and the viewing screen, how do you calculate for the new location of the 5th bright fringe?

Interference I 1. A plane wave is incident on the double slit. Light falls on double slits separated by 250 micrometers and the third-order minimum is observed at an angle of 0.25 degrees. What is the wavelength of light in nm? 3. Constructive interference occurs when r, and r, differ by a whole number of wavelengths. 2. Waves spread out behind each slit. Top view of the double slit 4. Destructive interference occurs when r, and r, differ by a whole. number of wavelengths plus half a wavelength. Front view of screen m-4 m=0 m=1 m=2 m=3 Interference m=4 Constructive interference Destructive interference Central maximum Path length difference for waves from two slits to a common point on a screen Constructive interference m=3 m=2 integer m, starting at the central maximum. Destructive interference Distance from central maximum to the mth bright fringe The bright fringes are labeled by the Al mà, for m=0, +1, +2, +3... Al = (m+), for m = 0, 21, 22, 23... Al = d sin 0 d sin emà, for m = 0,…

MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER What is the smallest separation between two slits that will produce a second-order minimum for 728 nm red light? 1.10 What is the relationship for destructive interference for a double slit? um Additional Materials O Reading

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