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 neutron is made of...

2 up quarks and 1 down quark.
1 up quark and 2 down quarks.
1 up quark and 1 down quark.

Question 2

I observed an object, larger than Earth but smaller than the Sun, which does not generate light by either deuterium or hydrogen fusion. What is it?

A planet.
A brown dwarf.
A star.

Question 3

A star is located on the top left of the H-R diagram. This star has...

High luminosity and low temperature.
Low luminosity and low temperature.
High luminosity and high temperature.

Question 4

Which of the following is a main-sequence star?

G2 IV
K6 V
B5 II

Question 5

Which of the following stars is the hottest?

K3
K9
K5

Question 6

Compared to Cepheid variables, RR Lyrae variables typically have...

Higher luminosity and shorter period.
Higher luminosity and longer period.
Lower luminosity and shorter period.

Question 7

Which is the dominant process used in a star with 2.7 solar masses to generate light?

The proton-proton chain.
The CNO cycle.
Deuterium fusion.

Question 8

I found a hydrogen-9 isotope. How many neutrons does it have?

8
7
6

Question 9

Object A has mass 1 kg. Object B has mass 9 kg. According to E=mc², how much rest energy does object B have compared to A?

3 times less energy.
3 times more energy.
9 times more energy.

Question 10

Star A has brighter absolute magnitude than star B. What does that say about the luminosity of the two stars?

Star A is more luminous.
Star B is more luminous.
There's no way to know unless we also know the distance to each star.

Question 11

Which of the following is the longest?

1 trillion kilometers.
1 light-year.
1 parsec.

Question 12

What kind of mass is defined as the strength of an object's gravitational field?

Gravitational mass.
Neither of the other options is correct.
Inertial mass.

Question 13

What happens to the mass in electron-positron annihilation?

Its rest energy is converted into kinetic energy of the produced photons.
Its rest energy is converted into gravitational potential energy of the produced photons.
The mass is conserved, and converted into the mass of the photons.

Question 14

In an atom, the electrons are located...

Inside the nucleus.
Either inside or outside the nucleus, depending on the type of atom.
Outside the nucleus.

Question 15

If the spectral lines of a star shift toward red, this means...

The star is moving toward us.
The star is not moving with respect to us.
The star is moving away from us.

Question 16

I want to measure the distance to a star that is estimated to be a few thousand light-years away. Which method should I use?

RR Lyrae variables
Cepheid variables
Stellar parallax

Question 17

A star was measured to have a parallax of 0.2 arc seconds. How far away is the star?

5 parsecs.
6 parsecs.
4 parsecs.

Question 18

I see a very faint star. This could mean:

Either the distance to the star is large or the luminosity of the star is large.
Either the distance to the star is large or the luminosity of the star is small.
Either the distance to the star is small or the luminosity of the star is large.

Question 19

In the H-R diagram, red dwarfs can be found...

At higher luminosity and lower temperature than the main sequence.
On the main sequence.
At higher luminosity and higher temperature than the main sequence.

Question 20

Which of the following stars is the least bright in the sky?

A star with apparent magnitude +3.1.
A star with apparent magnitude +7.0.
A star with apparent magnitude -4.4.

Question 21

A photon has a wavelength of 700 nm. What color is it?

Red.
Green.
Blue.

Question 22

In the proton-proton chain, how many total helium nuclei do we end up with?

1.
4.
2.

Question 23

Photon A has wavelength 2 cm. Photon B has wavelength 1 cm. Which photon has a higher frequency?

Photon B.
Both have the same frequency.
Photon A.

Question 24

Which of the following is a red dwarf?

M5 V
G2 V
O4 III

Question 25

If a particle has charge -1, what would be the charge of its antiparticle?

+1.
0.
-1.