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

Green.
Blue.
Red.

Question 2

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

8
7
6

Question 3

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 4

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 5

Which of the following is a main-sequence star?

G2 IV
B5 II
K6 V

Question 6

Object A has mass 1 kg. Object B has mass 3 kg. According to E=mc², how much rest energy does object B have compared to A?

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

Question 7

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 8

Which of the following stars is the hottest?

K3
K9
K5

Question 9

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

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

Question 10

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

-1.
+1.
0.

Question 11

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

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

Question 12

A proton is made of...

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

Question 13

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 brown dwarf.
A planet.
A star.

Question 14

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

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

Question 15

Which of the following is the longest?

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

Question 16

What happens in electron-positron annihilation?

An electron and a positron annihilate each other and produce 2 photons.
An electron and a positron annihilate each other and no photons are produced.
An electron and a positron annihilate each other and produce 1 photon.

Question 17

In the proton-proton chain, how many total hydrogen nuclei do we start with? (Remember that steps 1 and 2 happen twice in a full chain!)

2.
4.
1.

Question 18

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

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

Question 19

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

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

Question 20

A star was measured to have a parallax of 0.25 arc seconds. How far away is the star?

5 parsecs.
6 parsecs.
4 parsecs.

Question 21

Which of the following is a red dwarf?

O4 III
G2 V
M5 V

Question 22

In an atom, the protons are located...

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

Question 23

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

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

Question 24

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

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

Question 25

A star is located on the bottom right of the H-R diagram. This star has...

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