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 strongest magnetic field?

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

Question 2

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 3

Which force tries to expand every star throughout its life?

Pressure.
Electromagnetism.
Gravity.

Question 4

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 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.

Question 5

If a star has less mass...

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

Question 6

He II stands for...

Ionized helium.
Neutral helium.
Ionized hydrogen.

Question 7

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

Hot gas.
Molecular clouds.
H II regions.

Question 8

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

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

Question 9

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 10

Compared to white dwarfs, neutron stars are...

Just as dense.
More dense.
Less dense.

Question 11

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 12

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 13

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

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

Question 14

Which kind of region is the least common?

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

Question 15

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 16

A white dwarf...

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

Question 17

What is left after a Type Ia supernova?

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

Question 18

Approximately how long will the Sun spend in the red giant stage?

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

Question 19

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

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

Question 20

An emission nebula...

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

Question 21

Can a white dwarf have 1.2 solar masses?

No.
Depends on its radius.
Yes.

Question 22

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

Helium.
Iron.
Hydrogen.

Question 23

Which is the most dense?

Interstellar gas
Interstellar dust
Earth's atmosphere

Question 24

What prevents a white dwarf from collapsing?

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

Question 25

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.