Practice Test

Please solve the following questions. This is not a real exam, it will not be graded, and you do not need to submit your solutions to anyone. The questions are simply intended to help you practice for the real exam.

These questions will not appear in the exam itself. Students who don't genuinely attempt to solve the questions on their own, and only memorize the solutions, will have a very hard time in the actual exam!

This sample exam is online, but the real exam will be given in person, at a time and place indicated on the course website.

THIS IS NOT THE ACTUAL EXAM!
THIS IS JUST A PRACTICE EXAM!
THE REAL EXAM IS IN PERSON!

If you need any clarifications for these questions, you can ask for them on the course Teams channel.

Question 1

A reflection nebula...

Blocks light.
Scatters light from nearby stars.
Creates its own light.

Question 2

In the process of star formation, after hydrogen fusion begins, we have...

A main-sequence star.
A protostar.
A molecular cloud.

Question 3

I saw a planetary nebula in the sky. Where did it come from?

Material ejected from a planet near death.
Material ejected from a low-mass star near death.
Material ejected from a high-mass star near death.

Question 4

What is a nova?

An explosion that occurs when a new star is created.
An explosion that occurs when a white dwarf accumulates matter from its binary companion and approaches the Chandrasekhar limit.
An explosion that occurs when a white dwarf accumulates matter from its binary companion but does not approach the Chandrasekhar limit.

Question 5

He I stands for...

Neutral helium.
Ionized hydrogen.
Ionized helium.

Question 6

If a star has less mass...

Its lifetime is unaffected.
Its lifetime is shorter.
Its lifetime is longer.

Question 7

Can a white dwarf have 2.2 solar masses?

Yes.
Depends on its radius.
No.

Question 8

Which kind of region is the least common?

Both regions are equally common.
H II.
H I.

Question 9

When a star is starting in the main sequence, its core is made primarily of...

Hydrogen.
Helium.
Iron.

Question 10

Which force tries to expand every star throughout its life?

Pressure.
Gravity.
Electromagnetism.

Question 11

Most of the volume of interstellar gas is in the form of...

H II regions.
Hot gas.
Molecular clouds.

Question 12

Consider a star with an initial mass of 5 solar masses. What will be this star's final state?

A white dwarf.
A brown dwarf.
A neutron star.

Question 13

In which stage of its life will a star with mass similar to the Sun have the largest diameter?

Main sequence.
Red giant.
White dwarf.

Question 14

Compared to neutron stars, white dwarfs are...

More dense.
Just as dense.
Less dense.

Question 15

At the end of the life of a star with 20 solar masses, just before gravitational collapse, where would you expect to find iron?

In the outermost layer.
In the core.
In a middle layer.

Question 16

The end products of the triple-alpha process are...

Carbon nuclei.
Helium nuclei.
Beryllium nuclei.

Question 17

A white dwarf...

Produces faint light with stored heat energy.
Does not produce light anymore.
Produces bright light with energy from nuclear reactions.

Question 18

Which of the following has the strongest magnetic field?

A normal (rotation- or accretion-powered) pulsar.
A magnetar.
Planet Earth.

Question 19

What prevents a neutron star from collapsing?

Neutron degeneracy pressure and repulsion from the strong nuclear force.
Electron degeneracy pressure.
Pressure due to nuclear fusion.

Question 20

What are the most common particles in cosmic rays?

Protons.
Electrons or positrons.
Helium nuclei.

Question 21

The atoms in a gold ring were most likely created in...

A supernova.
A collision with an asteroid.
The core of a star.

Question 22

A rotation-powered pulsar is currently 9 million years old. When it was 1 million years old, it rotated...

Slower.
At the same speed.
Faster.

Question 23

What is the frequency of light emitted in a spin-flip transition?

21 GHz
1.4 GHz
5.9 GHz

Question 24

Which is bigger?

The Local Fluff.
The Local Bubble.
They are both the same size.

Question 25

Approximately how long will the Sun spend in the main sequence stage?

1.3 billion years.
5 million years.
11 billion years.