A layer of oil, with a refractive index of 1.40798, 0.92562 mm thick, floats on water.
a) Light of vacuum wavelength 632.800 nm, emitted with a stabilized He-Ne laser, is reflected at normal incidence by the oil. How many wavelengths are contained in the light wave passing back and forth during the oil?
b) Does the light reflected from the two surfaces of the oil interfere destructively or constructively?
Constructive interference structure interference