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

Which of the following has the weakest magnetic field?

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

Question 2

What are the least common particles in cosmic rays?

Electrons or positrons.
Helium nuclei.
Protons.

Question 3

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

Hydrogen.
Iron.
Helium.

Question 4

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

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

Question 5

The triple-alpha process starts by fusing together two...

Carbon nuclei.
Helium nuclei.
Beryllium nuclei.

Question 6

What is left after a Type Ia supernova?

A white dwarf.
A neutron star or a black hole.
Nothing.

Question 7

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 8

Can a white dwarf have 2.2 solar masses?

Yes.
Depends on its radius.
No.

Question 9

He I stands for...

Ionized hydrogen.
Ionized helium.
Neutral helium.

Question 10

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

Red giant.
White dwarf.
Main sequence.

Question 11

A reflection nebula...

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

Question 12

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

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

Question 13

What is a Type Ia supernova?

An explosion that occurs when a white dwarf accumulates matter from its binary companion but does not approach the Chandrasekhar limit.
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.

Question 14

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

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

Question 15

How long will a star with approximately 0.8 solar masses stay on the main sequence?

Approximately 10 million years.
Approximately 500 million years.
Approximately 14 billion years.

Question 16

A rotation-powered pulsar is currently 3 million years old. When it is 6 million years old, it will rotate...

Slower.
At the same speed.
Faster.

Question 17

If a star has more mass...

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

Question 18

Which is smaller?

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

Question 19

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

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

Question 20

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

Hot gas.
Molecular clouds.
H II regions.

Question 21

Which kind of region is the most common?

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

Question 22

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

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

Question 23

Compared to neutron stars, white dwarfs are...

Just as dense.
More dense.
Less dense.

Question 24

Which force tries to collapse every star throughout its life?

Pressure.
Gravity.
Electromagnetism.

Question 25

What is interstellar reddening?

The process where stars begin to emit more red light.
The process where stars turn into red dwarfs.
The process where light from stars becomes more red due to dust.