One of the two slits in a Young’s experiment is painted over so that it transmits only one-half the intensity of the other slit. As a result: 

A. the fringe system disappears 

B. the bright fringes get brighter and the dark ones get darker 

C. the fringes just get dimmer 

D. the dark fringes just get brighter 

E. the dark fringes get brighter and the bright ones get darker

If two light waves are coherent: 

A. their amplitudes are the same 

B. their frequencies are the same 

C. their wavelengths are the same 

D. their phase difference is constant 

E. the difference in their frequencies is constant

Bragg’s law for x-ray diffraction is 2d sin θ = mλ, where θ is the angle between the incident beam and: 

A. a reflecting plane of atoms 

B. the normal to a reflecting plane of atoms 

C. the scattered beam 

D. the normal to the scattered beam 

E. the refracted beam

Consider a single-slit diffraction pattern caused by a slit of width a. There is a maximum if sin θ is equal to: 

A. slightly more than 3λ/2a 

B. slightly less than 3λ/2a 

C. exactly 3λ/2a 

D. exactly λ/2a 

E. very nearly λ/2a

Which of the following is true for Bragg diffraction but not for diffraction from a grating? 

A. Two different wavelengths may be used 

B. For a given wavelength, a maximum may exist in several directions 

C. Long waves are deviated more than short ones 

D. There is only one grating spacing 

E. Maximum occur only for particular angles of incidence

Yellow light is viewed by reflection from a thin vertical soap film. Let λ be the wavelength of the light within the film. Why is there a large dark space at the top of the film?

A. no light is transmitted through this part of the film 

B. the film thickness there is λ/4 

C. the film thickness there is much less than λ 

D. the film is too thick in this region for thin film formulas to apply 

E. the reflected light is in the infrared

When the atmosphere is not quite clear, one may sometimes see colored circles concentric with the Sun or the Moon. These are generally not more than a few diameters of the Sun or Moon and invariably the innermost ring is blue. The explanation for this phenomena involves: 

A. reflection 

B. refraction 

C. interference 

D. diffraction 

E. the Doppler effect

An air wedge is formed from two glass plates that are in contact at their left edges. There are ten dark bands when viewed by reflection using monochromatic light. The left edge of the top plate is now slowly lifted until the plates are parallel. During this process: 

A. the dark bands crowd toward the right edge 

B. the dark bands remain stationary 

C. the dark bands crowd toward the left edge 

D. the dark bands spread out, disappearing off the right edge 

E. the dark bands spread out, disappearing off the left edge

Binoculars and microscopes are frequently made with coated optics by adding a thin layer of transparent material to the lens surface as shown. One wants:

A. constructive interference between waves 1 and 2 

B. destructive interference between waves 3 and 4 

C. constructive interference between 3 and 4 

D. the coating to be more transparent than the lens 

E. the speed of light in the coating to be less than that in the lens

Waves from two slits are in phase at the slits and travel to a distant screen to produce the third side maximum of the interference pattern. The difference in the distance traveled by the waves is: 

A. half a wavelength 

B. a wavelength 

C. three halves of a wavelength 

D. two wavelengths 

E. three wavelengths