Question 1

If the Sun collapsed to become a black hole, the Earth's gravitational attraction to it would be

Accepted Answer

A) more. 
B) less. 
C) no different. 
A) more. 
B) less. 
C) no different.

Question 2

What will halt the collapsing Sun's core once its fuel has been exhausted?

Accepted Answer

A) The inability of electrons to enter into neighboring electrons quantum state 
B) Outward thermal pressure 
C) Random quantum fluctuations 
D) The shift from fusion to fission nuclear reactions 
A) The inability of electrons to enter into neighboring electrons quantum state 
B) Outward thermal pressure 
C) Random quantum fluctuations 
D) The shift from fusion to fission nuclear reactions

Question 3

The event that changes a protostar to a full-fledged star is

Accepted Answer

A) gravitational collapse. 
B) gravitational expansion. 
C) thermonuclear fusion. 
D) the emission of light. 
E) a catastrophic increase in temperature. 
A) gravitational collapse. 
B) gravitational expansion. 
C) thermonuclear fusion. 
D) the emission of light. 
E) a catastrophic increase in temperature.

Question 4

Describe the fate of planet Earth if the Sun were to collapse to a black hole.

Accepted Answer

First of all, the orbit of the Earth wou

Question 5

If the Sun collapsed to a black hole, the time required for the Earth to orbit the collapsed Sun would

Accepted Answer

A) increase. 
B) decrease. 
C) stay the same. 
A) increase. 
B) decrease. 
C) stay the same.

Question 6

On the H-R diagram our Sun is a

Accepted Answer

A) white dwarf. 
B) star of average luminosity and temperature. 
C) red supergiant. 
D) relatively bright, blue star. 
A) white dwarf. 
B) star of average luminosity and temperature. 
C) red supergiant. 
D) relatively bright, blue star.

Question 7

A star's size stabilizes when

Accepted Answer

A) thermal pressure and gravitational attraction balance each other. 
B) the star's gravitational attraction is balanced by the gravitational attraction to neighboring stars. 
C) the star first ignites. 
D) it reaches temperatures of about 3 million K. 
A) thermal pressure and gravitational attraction balance each other. 
B) the star's gravitational attraction is balanced by the gravitational attraction to neighboring stars. 
C) the star first ignites. 
D) it reaches temperatures of about 3 million K.

Question 8

What event will eventually move an average star off the main sequence of the H-R diagram?

Accepted Answer

A) Running out of hydrogen, causing gravitational influx, resulting in core temperatures high enough to begin fusing helium 
B) Surface cooling due to hydrogen loss 
C) Solar wind storms 
D) Its drift through space due to the gravitational attraction of neighboring giant stars 
A) Running out of hydrogen, causing gravitational influx, resulting in core temperatures high enough to begin fusing helium 
B) Surface cooling due to hydrogen loss 
C) Solar wind storms 
D) Its drift through space due to the gravitational attraction of neighboring giant stars

Question 9

Which one of these elements is normally the remnant of a supernova?

Accepted Answer

A) hydrogen 
B) helium 
C) silver 
D) none of these 
A) hydrogen 
B) helium 
C) silver 
D) none of these

Question 10

An active galactic nucleus

Accepted Answer

A) is a place of intense star formation. 
B) arises from the gigantic black hole at the center of a galaxy. 
C) is a supermassive supergiant star that resides at the center of larger galaxies. 
D) is a giant dust cloud at the center of a galaxy. 
A) is a place of intense star formation. 
B) arises from the gigantic black hole at the center of a galaxy. 
C) is a supermassive supergiant star that resides at the center of larger galaxies. 
D) is a giant dust cloud at the center of a galaxy.

Question 11

A white dwarf is a former

Accepted Answer

A) low-mass star. 
B) high-mass star. 
C) white giant. 
A) low-mass star. 
B) high-mass star. 
C) white giant.

Question 12

What are the outward forces that act on a star? What are the inward forces? How do these compare?

Accepted Answer

The outward forces on a star are radiati

Question 13

All of the stars we see at night with our unaided eyes are within

Accepted Answer

A) 10,000 light-years, which is a small portion of our galaxy. 
B) 100,000 light-years, which encompasses most all of our galaxy. 
C) 5 million light-years, which encompasses our local group. 
D) 14 billion light-years, which encompasses the observable universe. 
A) 10,000 light-years, which is a small portion of our galaxy. 
B) 100,000 light-years, which encompasses most all of our galaxy. 
C) 5 million light-years, which encompasses our local group. 
D) 14 billion light-years, which encompasses the observable universe.

Question 14

A black hole is

Accepted Answer

A) a region of space that is collapsed in on itself. 
B) the result of the collapse of supergiant star. 
C) likely found at the center of each spiral galaxy. 
D) All of the above 
A) a region of space that is collapsed in on itself. 
B) the result of the collapse of supergiant star. 
C) likely found at the center of each spiral galaxy. 
D) All of the above

Question 15

A star's color tells us

Accepted Answer

A) how much energy a star produces. 
B) its surface temperature. 
C) its rotational speed. 
D) both how much energy it produces and its surface temperature. 
A) how much energy a star produces. 
B) its surface temperature. 
C) its rotational speed. 
D) both how much energy it produces and its surface temperature.

Question 16

A black hole has

Accepted Answer

A) about the same mass as the original star from which it formed. 
B) infinite mass. 
C) about half the mass of the star from which it formed. 
D) a mass that widely fluctuates. 
A) about the same mass as the original star from which it formed. 
B) infinite mass. 
C) about half the mass of the star from which it formed. 
D) a mass that widely fluctuates.

Question 17

The elements found on Earth have much to do with

Accepted Answer

A) white dwarfs. 
B) neutron stars. 
C) pulsars. 
D) quasars. 
E) supernovae. 
A) white dwarfs. 
B) neutron stars. 
C) pulsars. 
D) quasars. 
E) supernovae.

Question 18

Polaris is always directly overhead at

Accepted Answer

A) the north pole. 
B) any location north of the equator. 
C) the equator. 
A) the north pole. 
B) any location north of the equator. 
C) the equator.

Question 19

Our local group is composed of how many galaxies?

Accepted Answer

A) Less than 100 
B) Less than 400 
C) Less than 1,000 
D) 1,526 
A) Less than 100 
B) Less than 400 
C) Less than 1,000 
D) 1,526

Question 20

Compared to the event horizon, the photon sphere of a black hole is

Accepted Answer

A) nearer the singularity. 
B) farther from the singularity. 
C) at the same location. 
A) nearer the singularity. 
B) farther from the singularity. 
C) at the same location.

Exam 27: Stars and Galaxies

If the Sun collapsed to become a black hole, the Earth's gravitational attraction to it would be

What will halt the collapsing Sun's core once its fuel has been exhausted?

The event that changes a protostar to a full-fledged star is

Describe the fate of planet Earth if the Sun were to collapse to a black hole.

If the Sun collapsed to a black hole, the time required for the Earth to orbit the collapsed Sun would

On the H-R diagram our Sun is a

A star's size stabilizes when

What event will eventually move an average star off the main sequence of the H-R diagram?

Which one of these elements is normally the remnant of a supernova?

An active galactic nucleus

A white dwarf is a former

What are the outward forces that act on a star? What are the inward forces? How do these compare?

All of the stars we see at night with our unaided eyes are within

A black hole is

A star's color tells us

A black hole has

The elements found on Earth have much to do with

Polaris is always directly overhead at

Our local group is composed of how many galaxies?

Compared to the event horizon, the photon sphere of a black hole is

Patterns of Motion and Equilibrium

Newtons Laws of Motion

Momentum and Energy

Gravity, Projectiles, and Satellites

Fluid Mechanics

Thermal Energy and Thermodynamics

Heat Transfer and Change of Phase

Static and Current Electricity

Magnetism and Electromagnetic Induction

Waves and Sound

Light

Atoms and the Periodic Table

The Atomic Nucleus and Radioactivity

Elements of Chemistry

How Atoms Bond and Molecules Attract

Mixtures

How Chemicals React

Two Classes of Chemical Reactions

Organic Compounds

Rocks and Minerals

Plate Tectonics and Earths Interior

Shaping Earths Surface

Geologic Timereading the Rock Record

The Oceans, Atmosphere, and Climatic Effects

Driving Forces of Weather

The Solar System

The Structure of Space and Time

Prologue: the Nature of Science

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