A piece of glass has a thin film of gasoline floating on it. A beam of light is shining  perpendicular on the film. If the wavelength of light incident on the film is 560 nm and  the indices of refraction of gasoline and glass are 1.40 and 1.50, respectively, what is the  minimum thickness of the film to see a bright reflection?

33. You have a laser (a monochromatic light source) and want to estimate the wavelength. You decide to use a reflective diffraction grating to do this. The light is incident on the grating at 20 degrees with respect to normal. Using a grating with a groove distance of 5 um, the first-order diffraction, is found at an angle of -12.5 degrees. Determine the wavelength of the source. a) 500 nm b) 628 nm c) 808 nm d) 946 nm e) None of the above 34. In Raman spectrometry, Stokes lines have a) lower energy than that of anti-Stokes scattering. b) equal energy to that of anti-Stokes scattering. ) higher energy than that of anti-Stokes scattering d) none of the above 35. Upon ionization of phenol in aqueous solution, maximal UV absorbance changes to longer wavelength. a) True b) False 36. It takes longer time to observe fluorescence than phosphorescence. a) True b) False 37. The vibrational motion of C-H stretching in ethylene as in the figure can be detected by a) IR. b) Raman. c) IR and Raman.…

Yellow light (Ao = 560 nm) is NOT reflected in air by a thin film deposited on glass. If the thickness of the film is 100 nm and glass has a refractive index of nglass = 1.50, what is a possible value for the refractive index of the thin film? nair 1.00 100 nm Nthin film Nglass 1.50 O A. 1.1 оВ. 1.2 О С. 1.3 O D. 1.4

A thin film of polystyrene n=1.49 coats a piece of glass n=1.55. When illuminated from above, the dominant color of the light reflected to the observer is 473 nanometers wich is blue. What is the minimum thickness of the thin film? A. 317 nm B. 153 nm C. 159 nm D. 305 nm E. 79.4 nm

532 nm light is used on a 10.8 cm air wedge  to measure the thickness of a grain of sand. The distance between the centers of dark band 2 and dark band 8 is 0.22 cm.  What is the thickness of the grain of sand in micrometers?

A sodium light, having wavelength 589.3 nm, is used to view a soap film to make it look black when directed perpendicular to the film. What is the minimum thickness of the soap film if the index of refraction of soap solution is 1.38?

You are standing in air and are looking at a flat piece of glass (n = 1.52) on which there is a layer of transparent plastic (n = 1.61). Light whose wavelength is 640 nm in vacuum is incident nearly perpendicularly on the coated glass and reflects into your eyes. The layer of plastic looks dark. Find the smallest possible nonzero value for the thickness of the layer.

A flat piece of glass is held stationary and horizontal above the highly polished, flat top end of a 12.0-cm-long vertical metal rod that has its lower end rigidly fixed. The thin film of air between the rod and glass is observed to be bright by reflected light when it is illuminated by light of wavelength 490 nm. As the temperature is slowly increased by 21.5°C, the film changes from bright to dark and back to bright 200 times. What is the coefficient of linear expansion of the metal? °C-1