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

What is interstellar extinction?

The process where species of aliens become extinct.
The process where light from stars becomes dimmer.
The process where stars become extinct due to losing their hydrogen supply.

Question 2

In the process of star formation, after a core starts contracting but before hydrogen fusion begins, we have...

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

Question 3

He I stands for...

Ionized hydrogen.
Ionized helium.
Neutral helium.

Question 4

Which of the following has the strongest magnetic field?

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

Question 5

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

Slower.
Faster.
At the same speed.

Question 6

How much energy is emitted in a spin-flip transition?

1.4 micro electron volt
5.9 micro electron volt
21 micro electron volt

Question 7

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 white dwarf accumulates matter from its binary companion and approaches the Chandrasekhar limit.
An explosion that occurs when a new star is created.

Question 8

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

Helium.
Hydrogen.
Iron.

Question 9

An emission nebula...

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

Question 10

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

White dwarf.
Red giant.
Main sequence.

Question 11

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

Carbon nuclei.
Helium nuclei.
Beryllium nuclei.

Question 12

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

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

Question 13

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 14

Which is the least dense?

Earth's atmosphere
Interstellar dust
Interstellar gas

Question 15

Compared to white dwarfs, neutron stars are...

Less dense.
Just as dense.
More dense.

Question 16

Which force tries to expand every star throughout its life?

Electromagnetism.
Pressure.
Gravity.

Question 17

A white dwarf...

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

Question 18

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

Question 19

Which is bigger?

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

Question 20

Which kind of region is the most common?

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

Question 21

How long will a star with approximately 3.3 solar masses stay on the main sequence?

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

Question 22

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

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

Question 23

What are the least common particles in cosmic rays?

Helium nuclei.
Electrons or positrons.
Protons.

Question 24

Consider a star with an initial mass of 15 solar masses. What will be this star's final state?

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

Question 25

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

Molecular clouds.
Hot gas.
H II regions.