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

What is nuclear fusion?

The process where heavy nuclei split into lighter nuclei.
The process where light nuclei combine into heavier nuclei.
The process where nuclei are destroyed and converted into pure energy.

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?

Stellar parallax
RR Lyrae variables
Cepheid variables

Question 3

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

6
7
8

Question 4

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

Blue.
Green.
Red.

Question 5

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 6

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

Question 7

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

5 parsecs.
4 parsecs.
6 parsecs.

Question 8

A star is located on the top left of the H-R diagram. This star has...

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

Question 9

Which of the following is the shortest?

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

Question 10

Which of the following stars is the hottest?

K9
K3
K5

Question 11

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

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

Question 12

A neutron 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 13

What kind of mass is defined as resistance of an object to acceleration?

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

Question 14

I see a very bright 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 15

Which of the following is a bright giant?

G2 IV
B5 II
K6 V

Question 16

Which of the following is a blue giant?

M5 V
M2 III
O4 III

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!)

4.
1.
2.

Question 18

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

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

Question 19

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 20

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 21

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 22

What happens in electron-positron annihilation?

An electron and a positron annihilate each other and produce 1 photon.
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.

Question 23

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

-1.
+1.
0.

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 star.
A brown dwarf.
A planet.

Question 25

Which of the following stars is the brightest in the sky?

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