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

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

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

Question 2

Which of the following is a main-sequence star?

K6 V
G2 IV
B5 II

Question 3

What happens in electron-positron annihilation?

An electron and a positron annihilate each other and no photons are produced.
An electron and a positron annihilate each other and produce 1 photon.
An electron and a positron annihilate each other and produce 2 photons.

Question 4

Which of the following stars is the coolest?

K5
K9
K3

Question 5

Star A has brighter absolute 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.

Question 6

Which of the following is the longest?

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

Question 7

A star was measured to have a parallax of 0.25 arc seconds. How far away is the star?

5 parsecs.
4 parsecs.
6 parsecs.

Question 8

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

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

Question 9

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

Red.
Green.
Blue.

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 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 12

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

8
6
7

Question 13

In an atom, the protons are located...

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

Question 14

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

+1.
-1.
0.

Question 15

In the H-R diagram, red giants 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 16

What is nuclear fusion?

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

Question 17

A proton 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 18

Which of the following is a red dwarf?

G2 V
O4 III
M5 V

Question 19

If the spectral lines of a star shift toward blue, 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 20

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

Question 21

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 22

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 23

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 24

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

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

Question 25

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.
9 times more energy.
3 times more energy.