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

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

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

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

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 4

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

4 parsecs.
6 parsecs.
5 parsecs.

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

Question 6

Which of the following is the shortest?

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

Question 7

Which of the following is a red dwarf?

O4 III
M5 V
G2 V

Question 8

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

2.
4.
1.

Question 9

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 10

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

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

Question 11

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 brown dwarf.
A planet.
A star.

Question 12

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 13

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.

Question 14

Which of the following is a main-sequence star?

G2 IV
K6 V
B5 II

Question 15

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

8
6
7

Question 16

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

+1.
-1.
0.

Question 17

I see a very faint 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 large or the luminosity of the star is large.
Either the distance to the star is small or the luminosity of the star is large.

Question 18

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

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

Question 19

Which of the following stars is the coolest?

K5
K3
K9

Question 20

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

Green.
Blue.
Red.

Question 21

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

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

Question 22

In an atom, the electrons are located...

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

Question 23

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

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

Question 24

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

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

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.
3 times more energy.
9 times more energy.