(Electromagnetic spectrum/ waves ch 26-28) Physics
What is the frequency of an electromagnetic wave that has a wavelength of 300,000 km?
1 Hz
If the speed of light in a medium is 1.5×10^8 m/s, the medium's index of refraction is
2.0
A lunar eclipse occurs when the
Moon passes into Earth's shadow
Which of these electromagnetic waves has the shortest wavelength?
X-rays
At the same time an astronaut on the moon sees a solar eclipse, observers on Earth see
a lunar eclipse
Light travels fastest in
a vacuum
Materials generally become warmer when light is
absorbed by them
The greenish blue of water is evidence for the
absorption of red light
Amongst the following media, a beam of light travels fastest in
air
Atoms can be excited by
all of these
Interference is a property of
all of these
A single raindrop illuminated by sunshine disperses
all the colors of the rainbow
What color light is transmitted by a piece of blue glass?
blue
Rainbows exist because light is
both of these
What do electrons have that protons always have in equal magnitude?
charge
A sheet of red paper will look black when illuminated with
cyan light
Object and image for a plane mirror lie
equal distances from the mirror
If the sun were to disappear right now, we wouldn't know about it for 8 minutes because it takes 8 minutes
for light to travel from the sun to the earth
Different colors of light correspond to different light
frequencies
The energy of a photon depends on its
frequency
A mixture of cyan and yellow pigments appears
green
When a light beam emerges from water into air, the average light speed
increases
Most of the waves in the electromagnetic spectrum are
invisible to humans
Color depends on what characteristic of light
its frequency
Compared to its average speed in air, the average speed of a beam of light in glass is
less
Compared to ultraviolet waves, the wavelength of infrared waves is
longer
Light is emitted when an electron
makes a transition to a lower energy level
The main difference between a radio wave and a sound wave is their different
modes of travel
What is the wavelength of an electromagnetic wave that has a frequency of 1 hertz?
more than 1 m
A red crab very deep in water, where sunlight is dim, appears
no color - black
Electromagnetic waves consist of
oscillating electric and magnetic fields
When ultraviolet light is incident upon glass, atoms in the glass
resonate
Which of the following is fundamentally different from the others
sound waves
Refraction results from differences in light's
speed
Different colors are dispersed by a prism because different colors in the prism have different
speeds
Astronomers can tell whether a star is approaching or receding from Earth by
the Doppler effect
Compared to radio waves, the velocity of visible light waves in a vacuum is
the same
Consider light energy that is momentarily absorbed in glass and then re- emitted. Compared to the absorbed light, the frequency of the re-emitted light is
the same
Light will almost always travel from one place to another along a path of least
time
Light refracts when traveling from air into glass because light
travels slower in glass than in air
Sunburns are produced by
ultraviolet light
The highest frequency light of those below is
violet
Which color of light carries the most energy per photon?
violet
Your image in a plane mirror is
virtual
The complementary color of blue is
yellow
The brightest color emitted by the sun is
yellow-green