Conceptual
Physics Chapter 27 Test
27. Which choice best describes an electromagnetic
wave?
|
a. |
Electromagnetic waves are
transverse waves. |
c. |
Electromagnetic waves are
always very short. |
|
b. |
Electromagnetic waves are
longitudinal waves. |
d. |
Electromagnetic waves can
only travel in a vacuum. |
28. Which of these electromagnetic waves has the
shortest wavelength?
|
a. |
radio waves |
c. |
light waves |
|
b. |
infrared waves |
d. |
X-ray waves |
29. Compared to the velocity of radio waves, the
velocity of light waves is _____ .
|
a. |
faster |
c. |
the same |
|
b. |
slower |
d. |
constant |
30. Which one of these is the least like the other
three?
|
a. |
sound waves |
c. |
X-ray waves |
|
b. |
light waves |
d. |
gamma waves |
31. Which of these can be used to distinguish
between a light wave and a radio wave?
|
a. |
the speed of the wave |
c. |
the source of the wave |
|
b. |
the frequency of the wave |
d. |
the destination of the wave |
32. If the sun were to disappear
this instant, you would not know about it for eight minutes. This is because
_____ .
|
a. |
the sun is so large it
would take eight minutes for all of it to go away |
c. |
our eyes need eight minutes
for the human brain to fully process the light from the sun |
|
b. |
the sun is so far away that
it would take eight minutes for the light from the sun to reach Earth |
d. |
the dark that follows the
loss of light needs eight minutes to fully fill the space between Earth and
the sun |
33. Which of these best explains why metals have
shiny surfaces?
|
a. |
Metals hold electrons
loosely. |
c. |
The resonant frequency of
the electrons in the metal is very high. |
|
b. |
Metals are relatively
dense. |
d. |
Photons of light are
rejected by metal ions and reflect at a higher speed than when they entered
the metal. |
34. The light in a photographer’s dark room is
_____ because of all the colors of visible light photons of this color have the
least energy.
|
a. |
red |
c. |
green |
|
b. |
orange |
d. |
blue |
35. If an electron vibrates up and down 1000 times
each second, it generates an electromagnetic wave having a _____
|
a. |
period of 1000 s |
c. |
speed of 1000 m/s |
|
b. |
wavelength of 1/1000 m |
d. |
frequency of 1000 Hz |
36. When two polarizing filters are placed at right
angles to each other _____ of the light passes through the two filters.
|
a. |
0 % |
c. |
50 % |
|
b. |
33 % |
d. |
67 % |
39. Lightning strikes 17 kilometers away; if sound
travels at 340 m/s how many seconds will it take the thunder to reach you?
(Solve using the 3CM: 50 s is the final answer.)
40. Knowing that the speed of light is 3.0x108 m/s, what is the wavelength of an electromagnetic wave with a frequency of 1.0x105 Hz? (Remember that v = fl) Solve using the 3CM: 3 km, or 3000 m is the final answer)