Two parallel slits are illuminated by light composed of two wavelengths. One wavelength is AA = 594nm. The other wavelength is AB and is unknown. On a viewing screen, the light with wavelength AA = 594nm produces its third-order bright fringe at the same place where the light with wavelength AB produces its fourth dark fringe. The fringes are counted relative to the central or zeroth-order bright fringe. What is the unknown wavelength?

The distance between two slits is 1.50 × 10 -5 m. A beam of coherent light of wavelength 600 nm illuminates these slits, and the distance between the slit and the screen is 2.00 m. What is the distance on the screen between the central bright fringe and the fourth-order bright fringe? 0.201 m 0.324 m 0.132 m 0.528 m 0.688 m

** 38. Two plastic plates (index of refraction n = 1.3) are separated by an air gap of 0.9 µm. Analyze the reflections of light of wavelength 600 nm and conclude whether it will be brightly reflected or not. 0.9 um gap ** 39. The air gap in the previous problem is now filled with a mineral oil whose index of refraction is n = 1.5. Analyze the reflections of light of wavelength 600 nm and conclude if it will be brightly reflected or not.

What is the highest order dark fringe, m, that is found in the diffraction pattern for light that has a wavelength of 619 nm and is incident on a single slit that is 1400 nm wide? m=?