Temperature







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



Return to Table of Contents