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 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 2

Which of the following is a red dwarf?

G2 V
M5 V
O4 III

Question 3

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

6 parsecs.
4 parsecs.
5 parsecs.

Question 4

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

8
6
7

Question 5

Which of the following is the longest?

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

Question 6

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

Question 7

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 8

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 9

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

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

Question 10

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!)

1.
4.
2.

Question 11

Star A has brighter absolute 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 12

Which of the following is a bright giant?

B5 II
G2 IV
K6 V

Question 13

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.

Question 14

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 15

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

+1.
0.
-1.

Question 16

In an atom, the protons are located...

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

Question 17

Which of the following stars is the hottest?

K9
K3
K5

Question 18

A photon has a wavelength of 530 nm. What color is it?

Red.
Green.
Blue.

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

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

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

Question 21

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 22

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 23

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

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

Question 24

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 25

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.