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

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

Red.
Blue.
Green.

Question 2

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?

9 times more energy.
3 times less energy.
3 times more energy.

Question 3

I see a very bright star. This could mean:

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

Question 4

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 5

A star is located on the bottom right of the H-R diagram. This star has...

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

Question 6

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

5 parsecs.
6 parsecs.
4 parsecs.

Question 7

If the spectral lines of a star shift toward blue, 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 8

Which of the following is the longest?

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

Question 9

Which of the following stars is the least bright in the sky?

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

Question 10

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 11

Which of the following is a blue giant?

O4 III
M2 III
M5 V

Question 12

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

4.
1.
2.

Question 13

Which of the following is a bright giant?

B5 II
G2 IV
K6 V

Question 14

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

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

Question 15

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

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

Question 16

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 17

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 18

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 19

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 20

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

-1.
0.
+1.

Question 21

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 22

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 23

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 24

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

7
8
6

Question 25

Which of the following stars is the coolest?

K9
K5
K3