Exam 25: Interference and Diffraction

If the eye can resolve points separated by 2.2 × 10^-4 rad, how many dpi ensure you don't see individual dots when viewing something 12 inches away? (dpi = dots per inch)

In an x-ray diffraction experiment, x-rays of fixed wavelength yield a first-order maximum at an incident angle of 12° relative to the surface. At what angle would one expect to find the corresponding third-order maximum?

A thin film of soapy water (n = 1.37) is held vertical. Light of wavelength 600 nm is reflected from the film and horizontal dark lines appear. What is the thinnest soap film for which a bright band will occur?

Increasing the wavelength in a double-slit experiment has what effect on the position of the maxima on a screen at fixed distance?

Using a double slit with d = 300 nm and light of wavelength 400 nm, what would you see on a distant screen?

If a laser printer prints at 600 dots per inch, what is the angular separation of the dots when viewed from 40 cm?

The resolution of a microscope can be most improved by

What is the minimum thickness of the air layer between two flat glass surfaces if the glass is to appear bright when 450 nm light is incident normally?

Two coherent waves interfere constructively. One wave has an intensity of 8.00 I₀ and the other has an intensity of 4.00 I₀. What is the intensity of the superposed wave?

In a double-slit experiment, the intensity of the light reaching the center of the screen from one slit alone is I0 and intensity of the light reaching the center from the other slit alone is 9I0. When both slits are open, what is the intensity of the light at the minima nearest the center?

Two point sources of light of wavelength 600 nm are being viewed by a telescope with aperture width 2.0 cm. What is the smallest angular separation at which the two sources can be resolved?

When light of wavelength 700 nm is used in a single-slit diffraction pattern, the central maximum has a width of 3.5 cm. When the light source is replaced by one of wavelength 500 nm, what central width will result? Assume small angles.

Two coherent waves, each with amplitude A, are in phase as they overlap in a region of space. The amplitude of the superposed wave is

Two coherent waves, each with intensity I₀, are in phase as they overlap in a region of space. The intensity of the superposed wave is

When scattering x-rays with a wavelength of 3.28 × 10^-10 m from a crystal, the first interference maximum occurs at an angle of 23.0 degrees relative to the crystal surface. What is the crystal spacing?

X-rays of wavelength 0.080 nm are used in a Bragg scattering experiment with a crystal. If the first-order maximum is found at an incident angle of 6.0° relative to the crystal surface, what is the plane spacing in the crystal?

Two coherent sources emit waves of wavelength 2.0 m in phase. If the difference in path lengths to an observer is 7.0 m, what kind of interference occurs?

Light is shone through an adjustable-width slit in an otherwise opaque barrier, and a diffraction pattern is observed. If the slit is decreased to half its original size, by what factor does the width of the central diffraction maximum change?

For a coherent plane wave approaching an obstacle with a rectangular opening, diffraction becomes significant under which of the following circumstances?

In a double-slit interference pattern, the third maximum from the central maximum corresponds to which value of m?