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 force tries to collapse every star throughout its life?

Electromagnetism.
Gravity.
Pressure.

Question 2

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 3

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 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 4

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

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

Question 5

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

Red giant.
Main sequence.
White dwarf.

Question 6

Can a white dwarf have 1.2 solar masses?

No.
Depends on its radius.
Yes.

Question 7

A reflection nebula...

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

Question 8

Which kind of region is the most common?

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

Question 9

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

Hot gas.
Molecular clouds.
H II regions.

Question 10

Which of the following has the weakest magnetic field?

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

Question 11

He II stands for...

Neutral helium.
Ionized hydrogen.
Ionized helium.

Question 12

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

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

Question 13

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

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

Question 14

What is left after a Type Ia supernova?

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

Question 15

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

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

Question 16

What are the most common particles in cosmic rays?

Electrons or positrons.
Helium nuclei.
Protons.

Question 17

Compared to white dwarfs, neutron stars are...

More dense.
Less dense.
Just as dense.

Question 18

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

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

Question 19

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

Helium.
Iron.
Hydrogen.

Question 20

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

At the same speed.
Faster.
Slower.

Question 21

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

Question 22

A white dwarf...

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

Question 23

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

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

Question 24

What is interstellar reddening?

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

Question 25

What prevents a white dwarf from collapsing?

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