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

Which of the following is a main-sequence star?

B5 II
G2 IV
K6 V

Question 2

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 star.
A brown dwarf.
A planet.

Question 3

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

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

Question 4

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

7
6
8

Question 5

Which of the following is the shortest?

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

Question 6

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

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

Question 7

Which of the following is a blue giant?

O4 III
M5 V
M2 III

Question 8

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

-1.
+1.
0.

Question 9

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 10

A neutron is made of...

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

Question 11

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

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

Question 12

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

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

Question 13

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 14

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

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

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 see a very bright star. This could mean:

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

Question 17

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.
9 times more energy.
3 times less energy.

Question 18

Which of the following stars is the coolest?

K5
K3
K9

Question 19

In an atom, the electrons are located...

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

Question 20

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
Stellar parallax
RR Lyrae variables

Question 21

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 22

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

Green.
Red.
Blue.

Question 23

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

4.
1.
2.

Question 24

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 25

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