Section 19.1
Interference
Practice Test
1.
Why did Young place a single slit between the light source and the double slit?
a.
to filter out other colors of light
b.
to make the light waves coherent
c.
Light needs to escape the system.
d.
A single source of light is needed.
Hint
2.
An argon ion laser with a wavelength of 476.5 nm is used as the light source in a double slit experiment. If the slits are 0.0190 mm apart and the screen is 0.800 m away, what is the separation between the central bright line and the first-order bright line?
a.
18.6 mm
b.
21.3 mm
c.
20.1 mm
d.
19.1 mm
Hint
3.
Light results in a spectrum through a prism and interference on a thin film. This demonstrates that light behaves as __________.
a.
a particle only
b.
neither a particle nor a wave
c.
a wave
d.
a particle
Hint
4.
In a double slit experiment with slits 1.0×10
-5
m apart, light casts the first bright band 3.0×10
-2
m from the center of a screen 0.65 m away. What is the wavelength of this light?
a.
510 nm
b.
460 nm
c.
390 nm
d.
430 nm
Hint
5.
The spectrum of colors seen on a soap bubble is a result of __________.
a.
interference
b.
diffraction
c.
transparency
d.
diffusion
Hint
6.
Bright bands in interference fringes result from __________.
a.
destructive diffraction
b.
constructive interference
c.
destructive interference
d.
constructive diffraction
Hint
7.
Destructive interference in waves occurs when __________.
a.
crests and troughs align
b.
two crests overlap
c.
two troughs overlap
d.
a crest and a trough overlap
Hint
8.
The distance between the slits in a double-slit setup compared to the distance to the screen from the slits is __________.
a.
very large
b.
very small
c.
about the same
d.
not important in the experiment
Hint
9.
Thin film constructive interference occurs when the wavelength of a wave is in multiples of __________.
a.
4×wavelength
b.
1/4 wavelength
c.
1/2 wavelength
d.
2×wavelength
Hint
10.
In coherent waves, all wave crests and troughs __________.
a.
reach every other point at the same time
b.
reach the same point at the same time
c.
interfere destructively
d.
reach different points at different times
Hint
11.
Of the following, which is the best explanation for why the area at the top of the loop in Figure 19-6b is black?
a.
The constructive interference that is happening is for wavelengths out of the visible spectrum.
b.
There is no light passing through that area.
c.
There is no constructive interference taking place in that area.
d.
There is no soap film in that area.
Hint
