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.
Red.
Blue.

Question 2

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

RR Lyrae variables
Cepheid variables
Stellar parallax

Question 3

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

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

Question 4

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 5

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

+1.
-1.
0.

Question 6

Which of the following is a blue giant?

M5 V
M2 III
O4 III

Question 7

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

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

Question 8

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

Question 10

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

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

Question 11

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

4 parsecs.
6 parsecs.
5 parsecs.

Question 12

Which of the following stars is the brightest 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 13

Which of the following is the shortest?

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

Question 14

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 15

A proton 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 16

Which of the following stars is the coolest?

K5
K3
K9

Question 17

Which of the following is a main-sequence star?

G2 IV
B5 II
K6 V

Question 18

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 19

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 20

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.

Question 21

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

4.
2.
1.

Question 22

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

6
7
8

Question 23

In an atom, the protons are located...

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

Question 24

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

A brown dwarf.
A planet.
A star.

Question 25

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

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