A pair of narrow, parallel slits separated by 0.240 mm is illuminated by the gre
ID: 1676418 • Letter: A
Question
A pair of narrow, parallel slits separated by 0.240 mm is illuminated by the green component from amercury vapor lamp ( = 546.1 nm). The interferencepattern is observed on a screen 1.24 mfrom the plane of the parallel slits. (a) Calculate the distance from the centralmaximum to the first bright region on either side of the centralmaximum.1 mm
(b) Calculate the distance between the first and second dark bandsin the interference pattern.
2 mm (a) Calculate the distance from the centralmaximum to the first bright region on either side of the centralmaximum.
1 mm
(b) Calculate the distance between the first and second dark bandsin the interference pattern.
2 mm
Explanation / Answer
Given slitseparation d = 0.240mm = 2.40* 10-4 m distancebetween slits andscreen D = 1.24 m wavelength = 546.1 nm = 5.461* 10-7 m a. Positionof nthmaxima yn = n* D * / d forn = 1 y1 = 1* 1.24 * 5.461 * 10-7 / 2.40 * 10-4 = 2.82* 10-3 m = 2.82 mm = 2.82* 10-3 m = 2.82 mm b. Distance betwwen twodark fringes ( fringewidth) = D* / d= 1.24* 5.461 * 10-7 / 2.40 * 10-4
= 2.82 mm