Answers to Quiz #6 - Electromagnetic Waves, Optics, Special Relativity | PHYS 4D, Quizzes of Physics

Download Answers to Quiz #6 - Electromagnetic Waves, Optics, Special Relativity | PHYS 4D and more Quizzes Physics in PDF only on Docsity! Quiz6 Problem 1 In a two-slit interference experiment, the path length to a certain point  P on the screen differs for one slit in comparison to other by  1.25 . (a) What is the phase difference between the two waves arriving at point  P ? (b) Determine the intensity at  P , expressed as a function of the maximum intensity  I0 on the screen. Solution: (Ch 34, problem # 20) a) The phase difference is given in Eq. 34-4. We are given the path length difference, dsinθ. .5.2 25.1 2 sin 2          d b) The intensity is given by Eq. 34-6.   0 2 0 2 0 500.025.1cos2 cos IIII          Problem 2 Light of wavelength 690 nm passes through two narrow slits 0.66 mm apart. The screen is 1.6 m away. A second source of unknown wavelength produces its second order fringe 1.23 mm closer to the central maximum than the 690-nm light. What is the wavelength of the unknown light? (Hint: Use approximation of small angles  sin tan  ) Solution: (Ch. 34, problem #49 For constructive interference, the path difference is a multiple of the wavelength, as given by Eq. 34-2a. The location on the screen is given by x=l tanθ, as seen in Fig. 34-7(c). For small angles, we have sinθ=tanθ=x/l. second order means m=2. .440 ..,sin 12 21 21 2 2 1 1 nm ml xd d ml d ml xxx d ml x d ml xm l x dd       