Visible light of variable wavelength is incident normally on a thin sheet of plastic in air. The reflected light has a minima only for `lamba=512` nm and `lambda=640` nm in the visible spectrem. What is the minimum thickness (in mum) of the film `(mu=1.28)` ?

A thin film of soap solution (mu_(s)=1.5) . When visible light is incident almost normal to the plate, two wavelength 420 nm and 630 nm are strongly reflected. What is the minimum thickness (in nm) of the soap film?

A thin film having refractive index mu" = 1.5" has air on both sides. It is illuminated by white light falling normally on it. Analysis of the reflected light shows that the wavelengths 450 nm and 540 nm are the only missing wavelengths in the visible portion of the spectrum. Assume that visible range is 400 nm to 780 nm. (a) Find thickness of the film. (b) Which wavelengths are brightest in the interference pattern of the reflected light?

Blue light of wavelength 480 nm is most strongly reflected off a thin film of oil on a glass slab when viewed near normal incidence. Assuming that the index of refraction of the oil is 1.2 and that of the glass is 1.6, what is the minimum thickness of the oil film (other then zero)?

Blue light of wavelength 480 nm is most strongly reflected off a thin film of oil on a glass slab when viewed near normal incidence. Assuming that the index of refraction of the oil is 1.2 and that of the glass is 1.6, what is the minimum thickness of the oil film (other then zero)?

White light is incident normally on a glass plate (in air) of thickness 500 nm and refractive index of 1.5 . The wavelength (in nm ) in the visible region (400 nm-700nm) that is strongly reflected by the plate is:

White light is incident normally on a glass plate (in air) of thickness 500 nm and refractive index of 1.5 . The wavelength (in nm ) in the visible region (400 nm-700nm) that is strongly reflected by the plate is:

A light of wavelength 5890Å falls normally on a thin air film. The minimum thickness of the film such that the film appears dark in reflected light is

A light of wavelength 5890Å falls normally on a thin air film. The minimum thickness of the film such that the film appears dark in reflected light is

White light reflected at normal incidence from a soap film has minima at 6500Å and maxima at 7500Å in the visible region without minimum in between. If mu is (5)/(3) for the thin film, thickness of the film is