Exam 36: Applications of the Wave Model

Monochromatic light (λ = 500 nm) is incident on a soap bubble (n = 1.40). How thick is the bubble (in nm) if destructive interference occurs in the reflected light?

Monochromatic light from a He-Ne laser (λ = 632.8 nm) is incident on a diffraction grating containing 5000 lines/cm. Determine the angle of the first-order maximum.

A uniform film of oil (n = 1.31) is floating on water. When sunlight in air is incident normally on the film, an observer finds that the reflected light has a brightness maximum at λ = 450 nm and a brightness minimum at λ = 600 nm. What is the thickness of the oil film?

Monochromatic light (λ = 500 nm) is incident on a soap bubble (n = 1.40). What is the wavelength of the light (in nm) in the bubble film?

A film of index of refraction n₁ coats a surface with index of refraction n₂. When n₁ > n₂, the condition for constructive interference for reflected monochromatic light of wavelength λ in air is

Potassium Iodide (chemical formula: KI) has a face-centered cubic structure (just like sodium chloride). If the distance between crystal planes is d = 0.353 nm and X-rays of wavelength λ = 0.0934 nm are used, what is the smallest angle θ at which a diffraction maximum may be obtained?

Suppose two flat glass plates 30-cm long are in contact along one end and separated by a human hair at the other end. If the diameter of the hair is 50 μm, find the separation of the interference fringes when the plates are illuminated by green light, λ = 546 nm.

If the interplanar spacing of NaCl is 2.814 × 10−10 m, what is the predicted angle at which X-rays of wavelength 0.140 nm will be diffracted in a first-order maximum?

The light reflected from a soap bubble (n = 1.40) appears red (λ = 640 nm) at its center. What is the minimum thickness (in nm)?

At what distance could one theoretically distinguish two automobile headlights separated by 1.5 meters? Assume a pupil diameter of 0.50 cm and yellow headlights seen at the wavelength 5.0 × 10−7 m. Assume eye fluid has an average n = 1.33.

Nonreflective coatings for camera lenses reduce the loss of light at various surfaces of multi-lens systems, as well as preventing internal reflections that might mar the image. Find the minimum thickness of a layer of magnesium fluoride (n = 1.38) on flint glass (n = 1.66) that will cause destructive interference of reflected light of wavelength λ = 550 nm, a wavelength which is near the middle of the visual spectrum.