the heat contained in a substance depends directly both on the amount of substance present and on
A the volume
B whether it is a solid, liquid, or gas
C the temperature
D the chemical composition
star a appears bluish white in color, while star b appears reddish in color. this tells you that
A star a is less luminous than star b.
B star a is hotter than star b.
C star a is more luminous than star b.
D star a is cooler than star b.
the temperature of a gas is a measure of
A the number of atoms present
B the average speed of its atoms
C a combination of average speed and number of atoms
D an indefinable quantity associated with all materials
the peak wavelength of the radiation coming from a star
A will always be in the visible range
B will have no correlation with the apparent color of the star
C depends only on the pressure of the gases of the star's surface
D may be in the ultraviolet or the infrared range while the star is still visible
for a black body, at lower temperatures the brightest wavelength becomes
A shorter and fainter
B shorter and brighter
C longer and fainter
D longer and brighter
the frequency at which a star emits the most light depends upon the star's
A distance from us.
B brightness.
C temperature.
D eccentricity.
E velocity toward or away from us.
what is the relation between the color of a star and its temperature?
A the color of a star is a direct indicator of its temperature.
B the color of a star is not related to its temperature.
C the answer depends on what time of night the star is observed.
D the relationship is not fully known.
roughly what temperature does an object have to have to give off most of its energy in the form of visible light?
A a few hundred Kelvins
B a few thousand Kelvins
C a few tens of thousands of Kelvins
D a few million Kelvins
two bodies are the same size but body a has a temperature of 3000 k and body b has a temperature of 6000 K. if they both radiate according to the Planck curve, which will radiate the most red light?
A body a.
B body b.
C they will radiate the same amount of red light.
D you can't tell from the information given.
a black body radiation curve is observed when emitted light
A bounces around many times before leaving the object
B leaves the object immediately
C strips electrons from atoms
D is observed in a dark room
our bodies ordinarily emit
A visible light
B infrared light
C ultraviolet light
D radio waves
an object at room temperature emits light which is
A visible
B infrared
C radio
D ultra-violet
a black body
A is an object, covered with a special black paint, that does not absorb light the outside the visible spectrum
B is an ideal body which emits more radiation than falls on it
C is an ideal body which absorbs all radiation that falls on it
D is an ideal body which reflects all radiation that falls on it
for a black body, the wavelength distribution of emitted radiation depend s only on the object's
A mass
B visible brightness
C temperature
D chemical composition
the heat contained in a substance is
A equal to the temperature of the substance
B a combination of its temperature and its volume
C a combination of its temperature and the number of atoms present
D the speed with which the atoms move in the substance
a star's temperature can be found by
A measuring its "color"
B comparing its spectrum to that of a perfect radiator
C analyzing its dark line spectrum in detail
D all of the above
the heat contained in a substance depends directly both on the amount present and on
A its volume
B whether its a solid, liquid or gas
C its temperature
D how close it is to other hot substances
if each of the following objects is a perfect radiator, which is hottest
A a cloud of gas emitting radio waves
B an infrared star
C a lump of iron glowing with a "white" color
D the universe as seen in the microwave background radiation
the temperature of an object is a measure of the average
A weight of the atoms
B density of the object
C speed of the object
D speed of the atoms in the object
a star
A is too bright to be considered a black body
B radiates equally over the entire spectrum
C radiates over the entire spectrum, but the intensity peaks in a particular wavelength region
D radiates only at a few wavelengths, dependent on the color of the star
the brightest color of the sun is
A gamma ray
B infrared
C yellow-green
D ultraviolet
at absolute zero of temperature, which of the following conditions will ho
A all motion of atoms essentially ceases
B electrons stop moving around the nuclei of the atoms
C the color of all atoms (and materials) becomes the same
D the size of all atoms becomes vanishingly small
consider the sun's continuous emission as that of a black body radiator. then one way to infer the sun's surface temperature is to measure the
A longest wavelength the sun emits.
B shortest wavelength the sun emits.
C peak wavelength the sun emits.
D continuous spectrum after it passes through the air.
E dark lines in the continuous spectrum.
the surface temperature of the sun is about
A 90 f
B 900 f
C 9000 f
D 90,000 f
our sun emits its most intense radiation in which region of the electromagnetic spectrum
A infrared
B visible light
C ultraviolet
D x-rays
as the temperature of an object increases, its brightest wavelength
A increases
B decreases
C doesn't change
D changes in an unpredictable way.
a perfect absorber when illuminated with white light would appear to be
A white
B red
C blue
D black
the sun has an effective temperature of about 6000 k and its radiation peaks in the yellowish part of the spectrum. which of the following is true of a star that has an effective temperature of 10000 k?
A it will appear the same color as the sun.
B it will appear more blue than the sun.
C it will appear more red than the sun.
D you can't say anything about what color it will be.
as the temperature of an object is raised, the light it emits becomes
A redder
B bluer
C fainter
D Doppler shifted
a star's surface temperature is measured by observing the radiation in the star's spectrum which is
A longest
B shortest
C brightest
D weakest
the temperature of an object is determined by
A how fast the atoms are moving
B how many atoms are present
C both a and b
D whether an object is a gas, liquid or solid
the walls of this room radiate predominantly in which region of the electromagnetic spectrum
A radio
B infrared
C visible light
D ultraviolet
the color of a star is related to its
A temperature
B brightest wavelength
C spectral type
D all of these.
a star whose brightest color is in the infrared is
A cooler than the sun
B the same temperature as the sun
C hotter than the sun
D such stars do not exist
in a collection of atoms the higher the temperature the more frequent and violent the collisions and therefore
A the more atoms with electrons in excited states
B the fewer atoms with electrons in excited states
C temperature has nothing to do with the number of atoms with electrons in excited states
D the fewer atoms there will be
for stars, the shorter the brightest wavelength, the
A hotter the star
B cooler the star
C fainter the star
D higher the velocity of the star
if the effective temperature of a star is on the order of 3000 k, what color will the star be?
A red.
B yellow.
C blue.
D stars do not have colors that can be seen.
the "heat" contained in a sample is related to
A the temperature only
B the temperature and the quantity of material in the sample
C the average velocity of the atoms or molecules in the sample
D the density of the sample only
as an object is heated, its black body glow becomes bluer because
A the atoms begin to chemically react
B the electrons oscillate slower
C the atoms speed up
D the rules for electron orbits break down
the black body glow of an object at room temperature is
A visible
B ultraviolet
C microwave
D infrared
our sun emits its most intense radiation in what region of the electromagnetic spectrum?
A infrared
B visible
C ultraviolet
D x-ray
a star cooler than the sun will always appear, compared to the sun,
A bluer
B redder
C fainter in actual brightness
D brighter in actual brightness
if the sun were a cooler star, evolution of life would have favored (in terms of sight only) animals with eyes sensitive to
A ultraviolet light
B infrared light
C microwaves
D x-rays
an object at room temperature spontaneously emits mostly
A ultraviolet
B visible
C infrared
D radio
the temperature of a of gas (such as air) is a measure of
A the average distance between collisions of atoms
B the pressure of the gas
C how warm you feel in that atmosphere
D the average speed of the atoms of that gas
as an object becomes hotter,
A its brightest wavelength becomes shorter
B its brightest wavelength becomes longer
C its brightest wavelength doesn't change but it becomes more intense
D its brightest wavelength doesn't change but the band of bright wavelengths gets broader
ignoring details in its spectrum, the color of a star is an indication of its
A chemical composition
B size
C temperature
D mass
the "temperature" of a gas cloud in space is directly related to, and representative of
A the color of the cloud
B the average speed of its atoms
C the number of atomic collisions per second within the cloud
D the pressure of the gas cloud
if a star begins to increase its temperature, what will happen to the brightest wavelength of its emitted radiation?
A it will move towards longer wavelengths
B it will remain constant, since the state of the gas doesn't change
C it will not change, since it is not dependent upon temperature
D it will move towards shorter wavelengths
on the absolute scale of temperature (in degrees kelvin), the zero of the scale corresponds to
A the temperature at which all motion of atoms and matter ceases
B the melting point of ice
C the mean temperature of space
D the coldest temperature reached in the center of Antarctica
for a glowing body having the colors listed below, which would be the hottest
A red
B blue
C yellow
D black
the "color" or wavelength of maximum emission of radiation from a hot solid body (or a dense gas such as a star), when the body is cooled from a temperature of several thousand degrees, will
A remain absolutely constant, being dependent only upon the original color o the body
B remain fixed, until the body becomes invisible to the eye
C move towards the blue end of the spectrum
D move towards the red end of the spectrum
to what is the temperature of a thin gas most closely related?
A mean density of the gas
B average speed of the molecules
C mean pressure of the gas
D average number of collisions per second between molecules
a star whose brightest color is in the ultraviolet is
A about the same temperature as the sun
B cooler than the sun
C hotter than the sun
D larger than the sun
the temperature of an object depends on
A how many atoms are present and how fast the atoms are moving
B how many atoms are present
C how fast the atoms are moving
D whether the object is a solid, liquid, or gas
as the temperature of an object decreases, its brightest wavelength
A increases
B decreases
C doesn't change
D changes in an unpredictable way
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