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

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!)

1.
4.
2.

Question 2

A neutron 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 3

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

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

Question 4

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 5

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

6
7
8

Question 6

Which of the following stars is the coolest?

K5
K3
K9

Question 7

Which of the following is a red dwarf?

M5 V
O4 III
G2 V

Question 8

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

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

Question 9

Which of the following is the shortest?

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

Question 10

I see a very bright 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 11

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

-1.
0.
+1.

Question 12

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 13

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

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

Question 14

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

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

Question 15

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

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

Question 16

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

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

Question 17

Which of the following is a main-sequence star?

B5 II
G2 IV
K6 V

Question 18

What happens to the mass in electron-positron annihilation?

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

Question 19

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

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

Question 20

In an atom, the electrons are located...

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

Question 21

A photon has a wavelength of 530 nm. What color is it?

Red.
Green.
Blue.

Question 22

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

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

Question 23

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 24

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?

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

Question 25

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

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