PHY 205 Exam 2

A 'million million' is most nearly

10^12

Two stars are exactly the same size, but Star A is five times as luminous as star B. If the temperature of star B is 3000 K, then the temperature of star A is closest to A. 4500 K B. 5000 K C. 6000 K D. 15000 K

A. 4500 K

The wavelength of photon A is shorter than the wavelength of photon B. Which photon (A or B) has a higher frequency? A. A B. B C. They have the same frequency D. Cannot tell from information given

A. A

Imagine that you are the head of a funding agency that can afford to build only one telescope. Which of the four proposed telescopes below would be best to support? A. An ultraviolet telescope located in orbit around the earth B. A radio telescope in orbit around the earth C. A gamma ray telescope in a large, nearly parabolic crater in the salt flats of Utah. D. An x-ray telescope located on a mountain in Peru

A. An ultraviolet telescope located in orbit around the earth

If the stars Betelgeuse and Rigel were to have the same luminosity but the temperature of Betelgeuse is cooler than Rigel, which star has the greater surface area? A. Betelgeuse B. Rigel C. They are the same size. D. There is insufficient information to answer this question.

A. Betelgeuse

Which of the following is a later stage that every Main Sequence star experiences in its evolution, regardless of its mass? A. Giant B. Black hole C. White dwarf D. Supernova Type II

A. Giant

Java Star gives off much more light than Cola Star. Java and Cola are the same size. Which star has the higher temperature? A. Java B. Cola C. They have the same temperature. D. There is insufficient information to answer this question

A. Java

Which of the following lists, in the correct order, a possible evolutionary path for an isolated star? A. Main Sequence Star, Giant star, Planetary Nebula, White Dwarf B. Main Sequence Star, Giant star, Neutron Star, White Dwarf, Nothing C. Main Sequence Star, Giant star, Type I Supernova, Black Hole D. Main Sequence Star, Giant star, Type II Supernova, Planetary Nebula, Neutron Star E. Main Sequence Star, Giant star, Planetary Nebula, Black Hole

A. Main Sequence Star, Giant star, Planetary Nebula, White Dwarf

Which of the following lists, in the correct order, a possible evolutionary path for an isolated star? A. Main Sequence Star, Giant star, Type II Supernova, Black Hole B. Main Sequence Star, Giant star, Neutron Star, White Dwarf, Nothing C. Main Sequence Star, Giant star, Type I Supernova, Black Hole D. Main Sequence Star, Giant star, Type II Supernova, White Dwarf E. Main Sequence Star, Giant star, Planetary Nebula, Black Hole

A. Main Sequence Star, Giant star, Type II Supernova, Black Hole

Which of the following has the least energy? A. radio waves B. visible light C. x-rays D. infrared light E. They all have the same energy.

A. Radio waves

Rigel is much more luminous than Sirius B. Rigel and Sirius B have the same temperature. Which star has the greater surface area? A. Rigel B. Sirius B C. The have the same surface area. D. There is insufficient information to answer this question.

A. Rigel

Star A has a mass of 5 solar masses and Star B has a mass of 10 solar masses. How will the fusion rate of Star A compare to the fusion rate of Star B? A. Star A's fusion rate will be less than half that of Star B. B. Star A's fusion rate will be half that of Star B. C. Star A's fusion rate will be the same as that of Star B. D. Star A's fusion rate will be two times faster than that of Star B. E. Star A's fusion rate will be more than two times faster than that of Star B.

A. Star A's fusion rate will be less than half that of Star B.

Light with a high energy has a _____ frequency and a _____ wavelength A. high; short B. high; long C. low; short D. low; long

A. high; short

Because the speed of light is constant, a light-year _________. A. is a fixed distance B. is a fixed amount of time C. is a distance that varies depending on how fast the light is going D. is an amount of time that varies depending on how fast the light is going

A. is a fixed distance

Energy is released from atoms in the form of light when electrons A. move from high energy levels to low energy levels. B. move in their orbit around the nucleus. C. move from low energy levels to high energy levels. D. are emitted by the atom. E. are absorbed by atoms.

A. move from high energy levels to low energy levels.

Where are elliptical galaxies more common? A. toward the centers of galaxy clusters B. toward the outer edges of galaxy clusters C. outside clusters of galaxies D. they are equally prevalent everywhere

A. toward the centers of galaxy clusters

The gap between energy levels ________ as you go up in energy levels. A. will get smaller B. will get bigger C. will not change

A. will get smaller

What is a light year? A. An interval of time B. A measure of length C. An indication of speed D. All of the above

B. A measure of length

In which one of the galaxies would you expect to see mostly red stars? A. A spiral galaxy B. An elliptical galaxy C. Neither a spiral nor an elliptical galaxy D. Both spiral and elliptical galaxies

B. An elliptical galaxy

Which of the following has the most energy? A. Red light B. Blue light C. Yellow light D. All of the above have the same energy because they are all visible light

B. Blue light

A 0.8 solar mass red giant is observed in a binary with a 0.5 solar mass white dwarf companion. Which statement is true? A. The red giant has likely always had a mass greater than the white dwarf companion. B. The red giant likely had less mass than its companion when these stars first formed. C. This binary could produce a type II supernova D. This binary could produce a type Ia supernova E. This binary has already produced a type II supernova.

B. The red giant likely had less mass than its companion when these stars first formed.

Why do elliptical galaxies not produce new, young stars? A. They are not massive enough. B. They do not have enough gas and dust. C. They do not experience enough internal pressure. D. Elliptical galaxies actually do produce new, young stars.

B. They do not have enough gas and dust.

Which of the following is true for novas? A. They occur with all white dwarfs B. They occur only when a white dwarf has a companion star C. They occur when a star has a large mass D. They occur with all neutron stars E. They occur only when a neutron star has a companion star

B. They occur only when a white dwarf has a companion star

How many of the following: gamma, x-ray, UV, Visible, IR and radio, coming from space can pass through the atmosphere without being absorbed at all? A. Only one B. Two C. Three D. More than Three E. None of the above

B. Two

You are making a hot pocket in your microwave and you see that the inside of the appliance is illuminated. What type of radiation are you observing with your eyes? A. Radio B. Visible C. Microwave D. X-ray

B. Visible

Main sequence stars begin life as A. a white dwarf,. B. a cloud of gas and dust. C. a very large hot planet. D. a red giant.

B. a cloud of gas and dust.

On an H-R diagram, stars at the same temperature are found A. aligned horizontally (i.e., side-by-side). B. aligned vertically (i.e., one above the other). C. next to each other on the main sequence. D. near the bottom of the diagram E. near the top of the diagram

B. aligned vertically (i.e., one above the other).

Plastic is made largely of carbon and oxygen (but with many variations and other elements too). The atoms in the plastic of your chair were formed A. in our Sun. B. by a star existing prior to the formation of our Sun. C. at the instant of the Big Bang. D. approximately 100 million years ago. E. in a distant galaxy in a different part of the early universe

B. by a star existing prior to the formation of our Sun.

When the Milky Way eventually collides with Andromeda, which type(s) of galaxy most likely results from the collision? A. spiral B. elliptical C. either an elliptical or a spiral galaxy could form D. There is no way to tell.

B. elliptical

During the beginning of star formation, The force that dominates the collapse of the gas and dust is A. electrostatic. B. gravity. C. magnetism. D. friction.

B. gravity.

A galaxy that appears to have very few bright, blue stars, likely: A. never had blue stars in the galaxy B. had blue stars that are not present anymore but were at one time long ago C. has been around long enough for the blue stars to have evolved into red main sequence stars D. never contained enough gas to have blue stars develop E. has blue stars that are being blocked by dust

B. had blue stars that are not present anymore but were at one time long ago

In a main sequence star, gravitational collapse is balanced by A. convection of stellar material from the core. B. pressure caused by photons produced during nuclear fusion. C. solid material at the stellar core. D. pressure from coronal mass ejections from the core. E. interior cooling of the star.

B. pressure caused by photons produced during nuclear fusion.

Which of the different wavelengths of light listed below completely passes through Earth's atmosphere and reaches the surface? A. gamma B. radio C. infrared D. X-rays E. All of the above.

B. radio

The HR Diagram at right is provided to assist with answering the following questions. Which is hotter, a main sequence star or a white dwarf, both of which have a luminosities 100 times less than the Sun? A. the main sequence star B. the white dwarf C. They have the same temperature. D. There is insufficient information to determine this.

B. the white dwarf

The total main sequence lifetime of stars like the Sun is about A. 1 million years. B. 10 million years. C. 10 billion years. D. 100 billion years.

C. 10 billion years.

In class we looked at the Hubble Ultra Deep Field, an image taken by focusing the Hubble Space Telescope on an empty patch of sky for almost 12 days in order to resolve very faint very distant galaxies. The image shows 10,000 galaxies in an area of the sky 1% the size of the moon. Assuming the HUDF is representative of the entire universe, and knowing that the moon covers one one-millionth of the entire sky, approximately how many galaxies are exist in the observable universe? A. 10^6 B. 10^8 C. 10^12 D. 10^24 E. 10^96

C. 10^12

You are observing a star that is 250 million light years away. From the starlight you are observing now, the appears to be 30 million years old and you determine that the star has a lifetime of 120 million years. How long will it be until Earth receives light from the supernova that occurs at the end of the life of the star? A. 250 million years B. 120 million years C. 90 million years D. 160 million years

C. 90 million years

If our Sun quadrupled in mass, what would it become when it died? A. A black hole B. A white hole C. A white dwarf D. A neutron star E. A proton star

C. A white dwarf

Which of the following has the shortest wavelength? A. A photon of ultraviolet light. B. Blue electromagnetic radiation. C. An X-ray. D. A radio wave. E. Infrared radiation.

C. An x-ray

When you view a spiral galaxy, why do you not see much red light? A. Red stars are blocked by gas and dust. B. All of the red stars have died out in spiral galaxies. C. Blue stars in spiral galaxies are much brighter than red stars. D. Spiral galaxies do not produce many red stars.

C. Blue stars in spiral galaxies are much brighter than red stars.

Enzo star gives off the same amount of energy as Ferdinand star. But Enzo star is much, much hotter than Ferdinand star. Which star has the greater surface area? A. They have the same surface area B. Enzo C. Ferdinand D. There is insufficient information to answer this question.

C. Ferdinand

Chili Pepper is a main sequence star that appears red when viewed from Earth, as a result which of the following is (always) true: A. It is hotter than an O spectral type main sequence star. B. It will appear brighter than a white dwarf. C. It will live longer than a B spectral type main sequence star. D. It is the same size as a red giant star of the same temperature. E. None of the above are correct

C. It will live longer than a B spectral type main sequence star.

Which of the following sequences of spectral types represent the coolest to hottest stars? A. ABFGKMO B. OMKGFBA C. MKGFABO D. MFKGABO

C. MKGFABO

Consider the information given below about three main sequence stars A, B, and C. Star A will be a main sequence star for 4.5 billion years. Star B has the same luminosity as the Sun. Star C has a spectral type of M5. Which of the following is a true statement about these stars? A. Star A has the greatest mass. B. Star B has the greatest mass. C. Star C has the greatest mass. D. Stars A, B and C all have approximately the same mass. E. There is insufficient information to determine this.

C. Star C has the greatest mass.

Why are the spiral arms of spiral galaxies typically blue in color? A. They are usually moving toward us and are Doppler shifted to blue wavelengths. B. The gas and dust in the arms filter out all but the blue light from stars in the arms. C. Stars are forming in the spiral arms so there are many more high mass, hot, blue stars. D. Almost all the stars of the disk are in the arms of the galaxy and their light makes it appear blue.

C. Stars are forming in the spiral arms so there are many more high mass, hot, blue stars.

Which of the following would be true about comparing visible light and radio waves? A. The radio waves would have a lower energy and would travel slower than visible light. B. The visible light would have a shorter wavelength and a lower energy than radio waves. C. The radio waves would have a longer wavelength and travel the same speed as visible light. D. The visible light would have a higher energy and would travel faster than radio waves. E. The radio waves would have a shorter wavelength and higher energy than visible light.

C. The radio waves would have a longer wavelength and then travel the same speed as visible light.

How does the size of a star near the top left of the H-R diagram compare with a star of the same luminosity near the top right of the H-R diagram? A. They are the same size. B. The star near the top left is larger. C. The star near the top right is larger. D. There is insufficient information to determine this.

C. The star near the top right is larger.

Stars that are red: A. Are moving toward Earth. B. Are moving away from Earth. C. There is not enough information to determine the stars' movement.

C. There is not enough information to determine the stars' movement.

If an electron in an atom moves from an energy level of 5 to an energy level of 10, A. a photon of energy 5 is emitted. B. a photon of energy 15 is emitted. C. a photon of energy 5 is absorbed. D. a photon of energy 15 is absorbed.

C. a photon of energy 5 is absorbed.

One way to trigger the collapse of a region of gas and dust where a star will form is A. the spiraling motion of the gas and dust particles. B. the absorption of infrared radiation from nearby stars. C. a shockwave from a nearby supernova. D. the energy given off by nuclear fusion. E. the high temperature of the gas and dust particles.

C. a shockwave from a nearby supernova.

The space between the spiral arms of the Milky Way contains A. density waves. B. little dust and few stars. C. about the same number of stars as in the arms. D. only reflection and emission nebulae.

C. about the same number of stars as in the arms.

The eventual fate of our Sun is to A. collapse into black hole. B. form a neutron star. C. become a steadily cooling white dwarf. D. explode as a type Ia supernova, leaving no remnant.

C. become a steadily cooling white dwarf.

The total number of galaxies in the universe is _________ while galaxies are becoming ________ . A. increasing, more massive B. increasing, less massive C. decreasing, more massive D. decreasing, less massive

C. decreasing, more massive

Which of the following has the most energy? A. radio waves B. visible light C. x-rays D. infrared light E. They all have the same energy.

C. x-rays

Roughly how many planets should we expect to exist in the observable universe? There are approximately 100 billion galaxies, each with 100 billion stars. A. 10^11 B. 10^18 C. 10^19 D. 10^23 E. 10^27

D. 10^23

Imagine you are comparing the five stars (A-E, shown below) of different sizes and temperatures. The temperature of each star is indicated by a shade of gray (as shown at right), such that the lighter the shade of gray, the higher the temperature of the star. Which of the following is the most correct ranking for the luminosity of these stars from greatest to least? A. A > B = C = E > D B. E = A > C > D = B C. B > C > E > D > A D. A > E > C > B > D E. D > B > C > E > A

D. A > E > C > B > D

Which of the following has the longest wavelength? A. A photon of ultraviolet light. B. Blue electromagnetic radiation. C. An X-ray. D. A radio wave. E. Infrared radiation.

D. A radio wave

Which of the following is not a form of light? A. radio waves B. microwaves C. x-rays D. All of the above are a form of light. E. None of the above is a form of light

D. All of the above are a form of light

The diagram at right represents three different waves of light emitted at the same time by the Sun. Which wave will arrive first at a satellite orbiting just above Earth's atmosphere? A. Wave 1 B. Wave 2 C. Wave 3 D. All three waves arrive at the same time.

D. All three waves arrive at the same time.

Two stars A and B are exactly the same size, but the surface temperature of star A is 5000 K, while the surface temperature of star B is 10,000 K. How does the luminosity of the brighter star B compare to star A? A. If the same size, then the stars are the same luminosity. B. B is twice as luminous as A C. B is 4 times as luminous as A D. B is 16 times as luminous as A E. There is insufficient information to answer this question.

D. B is 16 times as luminous as A

What is the spectral type of the Sun? A. O B. B C. F D. G E. K

D. G

Rank the speed, from fastest to slowest, of the following light forms: Gamma rays, UV, Radio, X-rays, and Infrared: A. Gamma rays, X rays, UV, Infrared, Radio B. Radio, Infrared, UV, X-rays, Gamma Rays C. Gamma rays, UV, Infrared, Radio, X-rays D. None of the above

D. None of the above

Some telescopes are placed in space above Earth's atmosphere primarily for which of the following reasons? A. Because the astmosphere magnifies objects making them look larger than they actually are. B. Some of the light being sent out from the telescopes can be blocked by Earth's atmosphere. C. Moving the telescope above the atmosphere puts the telescope closer making the objects appear brighter. D. Some of the light from objects is absorbed by Earth's atmosphere.

D. Some of the light from objects is absorbed by Earth's atmosphere.

Which statement is the most correct about the comparison between a spectral type G main sequence star and a spectral type O main sequence star? A. The G star is cooler, dimmer, smaller, and will not live as long as the O star. B. The G star is hotter, brighter, smaller, and will live longer than the O star. C. The G star is smaller, hotter, brighter, and will not live as long as the O star. D. The G star is dimmer, cooler, smaller, and will live longer than the O star. E. The G star is hotter, dimmer, larger, and will live longer than the O star.

D. The G star is dimmer, cooler, smaller, and will live longer than the O star.

Imagine you are observing two stars. One star is hot and small and the other star is cooler and larger. Which star is more luminous? A. the hotter star B. the larger star C. They have the same luminosity. D. There is insufficient information to answer this question.

D. There is insufficient information to answer this question.

Which of the following would most likely give off the most energy? A. a red star half the size (diameter) of the Sun B. a red star 10 times the size (diameter) of the Sun C. a blue star half the size (diameter) of the Sun D. a blue star 10 times the size (diameter) of the Sun

D. a blue star 10 times the size (diameter) of the Sun

Typical distances between stars in the Milky Way are A. a few light seconds B. a few light minutes C. a few light hours D. a few light-years

D. a few light-years

A star is moving toward Earth. If you were to look at the spectrum of this star, what would it look like? A. an absorption spectrum that is redshifted relative to an unmoving star B. an emission spectrum that is redshifted relative to an unmoving star C. a continuous spectrum that is blueshifted relative to an unmoving star D. an absorption spectrum that is blueshifted relative to an unmoving star E. a continuous spectrum that is redshifted relative to an unmoving star

D. an absorption spectrum that is blueshifted relative to an unmoving star

Compared to stars on the lower right-hand part of the main sequence, stars on the upper left-hand part of the main sequence (choose all that apply) A. are redder. B. are cooler. C. have longer lifetimes. D. are more luminous. E. are smaller.

D. are more luminous.

If we wait a very long time, our universe will have A. more spiral galaxies and more elliptical galaxies B. more spiral galaxies and fewer elliptical galaxies C. fewer spiral galaxies and fewer elliptical galaxies D. fewer spiral galaxies and more elliptical galaxies

D. fewer spiral galaxies and more elliptical galaxies

Light with a very short wavelength has a _____ frequency and _____ energy. A. high; low B. low; high C. low; low D. high; high

D. high; high

How will the fusion rate of a two solar mass star compare to the fusion rate of a four solar mass star? A. They will have the same fusion rate. B. The more massive star will have twice the fusion rate. C. The more massive star will have a fusion rate that is two times slower. D. none of the above

D. none of the above

A star with a mass twice that of the sun could be A. a red giant star B. a white dwarf C. a neutron star D. two of the above E. all the above.

D. two of the above

Suppose we wanted to compress Colin to the highest density possible. What kind of star should we drop him on? A. A low mass main sequence star B. A high mass main sequence star C. A white dwarf D. A red giant E. A neutron star

E. A neutron star

Which of the following do spiral galaxies contain? A. O-type main sequence stars B. M-type main sequence stars C. A-type main sequence stars D. Gas and dust E. All of the above

E. All of the above

You are skimming a magazine article and see an article about 'Krootabulon.' You aren't reading too closely and you've never heard of Krootabulon before, but halfway through the article a sentence catches your eye which reads 'Krootabulon is 170 million lightyears away.' You can pretty confidently conclude that A. Krootabulon is an object in our solar system. B. Krootabulon is outside the solar system but relatively nearby. C. Krootabulon is far outside the solar system but still within the Milky Way. D. Krootabulon is far outside the Milky Way but still somewhere within the Local Group E. Krootabulon is very far outside the Local Group.

E. Krootabulon is very far outside the Local Group.

Which is true of Doppler Shifted light from a star? A. If the light is redshifted, the star is moving towards you. B. If the light is blueshifted, the star is close to you. C. If the light is redshifted, the star is moving quickly. D. If the light is blueshifted, the star will appear blue. E. None of the above is true.

E. None of the above is true.

Which of the following moves the slowest? A. radio waves B. visible light C. x-rays D. infrared light E. They all move at the same speed.

E. They all move at the same speed.

A star on the lower right-hand part of the main sequence will ______ than a star on the upper left-hand part of the main sequence. A. have a shorter lifetime. B. be hotter. C. be larger. D. be more luminous. E. be less massive

E. be less massive

Which of the following determines most characteristics and future events of a star's existence? A. surface temperature B. size (diameter) C. color D. composition (type of atoms) E. mass

E. mass

A main sequence star with 25 times the mass of the Sun may eventually A. produce a type II supernova only if it has a companion star B. produce a black hole only if it has a companion star C. produce a neutron star only if it has no companion star D. more than one of the above statements is correct E. none of the above statements are correct

E. none of the above statements are correct

A kilonova is produced A. the same as a nova, by accretion onto a white dwarf. B. by a supernova which collapses to to a black hole, resulting in a weak explosion. C. when two white dwarfs collide. D. when two black holes collide. E. when two neutron stars collide.

E. when two neutron stars collide.

Which of the following has the highest speed? A. x-rays B. ultraviolet light C. gamma rays D. They all have the same speed.

They all have the same speed.