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 black dwarf...

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

Question 2

Can a white dwarf have 2.2 solar masses?

Depends on its radius.
No.
Yes.

Question 3

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 a middle layer.
In the core.

Question 4

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

Molecular clouds.
Hot gas.
H II regions.

Question 5

What is a Type Ia supernova?

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 6

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

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

Question 7

If a star has more mass...

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

Question 8

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

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

Question 9

What is left after a Type II supernova?

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

Question 10

What prevents a neutron star from collapsing?

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

Question 11

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

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

Question 12

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

At the same speed.
Slower.
Faster.

Question 13

A reflection nebula...

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

Question 14

Compared to white dwarfs, neutron stars are...

Just as dense.
Less dense.
More dense.

Question 15

Which of the following has the weakest magnetic field?

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

Question 16

Which is bigger?

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

Question 17

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

Main sequence.
White dwarf.
Red giant.

Question 18

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

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

Question 19

Which is the most dense?

Earth's atmosphere
Interstellar gas
Interstellar dust

Question 20

Which kind of region is the least common?

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

Question 21

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

Carbon nuclei.
Helium nuclei.
Beryllium nuclei.

Question 22

What are the least common particles in cosmic rays?

Protons.
Electrons or positrons.
Helium nuclei.

Question 23

What is interstellar extinction?

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

Question 24

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

Iron.
Helium.
Hydrogen.

Question 25

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

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