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

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

Question 2

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 3

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

8
7
6

Question 4

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 5

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 away from us.
The star is moving toward us.

Question 6

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 7

Which of the following stars is the coolest?

K5
K3
K9

Question 8

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

-1.
0.
+1.

Question 9

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

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

Question 10

What happens to the mass in electron-positron annihilation?

The mass is conserved, and converted into the mass of the photons.
Its rest energy is converted into gravitational potential energy of the produced photons.
Its rest energy is converted into kinetic energy of the produced photons.

Question 11

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 12

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 13

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 planet.
A star.
A brown dwarf.

Question 14

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

Green.
Red.
Blue.

Question 15

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 16

I want to measure the distance to a star that is estimated to be a few thousand light-years away. Which method should I use?

RR Lyrae variables
Stellar parallax
Cepheid variables

Question 17

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

2.
4.
1.

Question 18

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 19

Which of the following is a red dwarf?

O4 III
M5 V
G2 V

Question 20

Which of the following is a bright giant?

K6 V
B5 II
G2 IV

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

In the H-R diagram, red giants 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 23

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 24

Which of the following is the shortest?

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

Question 25

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

4 parsecs.
5 parsecs.
6 parsecs.