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 530 nm. What color is it?

Red.
Green.
Blue.

Question 2

In the H-R diagram, red giants 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 3

Which of the following is a main-sequence star?

B5 II
G2 IV
K6 V

Question 4

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

-1.
+1.
0.

Question 5

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 6

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

6 parsecs.
5 parsecs.
4 parsecs.

Question 7

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 8

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

7
6
8

Question 9

Which of the following stars is the brightest 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 10

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 star.
A brown dwarf.
A planet.

Question 11

Which of the following is the longest?

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

Question 12

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

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

Question 13

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 14

Which of the following is a red dwarf?

G2 V
M5 V
O4 III

Question 15

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 16

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?

Cepheid variables
RR Lyrae variables
Stellar parallax

Question 17

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

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

Question 18

I see a very faint star. This could mean:

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

Question 19

In an atom, the electrons are located...

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

Question 20

Star A has brighter apparent 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 21

Which of the following stars is the coolest?

K9
K3
K5

Question 22

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 23

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 24

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

1.
4.
2.

Question 25

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

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