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

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

8
6
7

Question 2

Which of the following is a bright giant?

G2 IV
K6 V
B5 II

Question 3

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

Red.
Blue.
Green.

Question 4

Which of the following is the longest?

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

Question 5

Star A has brighter apparent magnitude than star B. What does that say about the luminosity of the two stars?

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

Question 6

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 7

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 8

Which of the following is a red dwarf?

G2 V
O4 III
M5 V

Question 9

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 10

A neutron is made of...

2 up quarks and 1 down quark.
1 up quark and 1 down quark.
1 up quark and 2 down quarks.

Question 11

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 12

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

Question 13

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?

Cepheid variables
RR Lyrae variables
Stellar parallax

Question 14

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 15

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.
2.
4.

Question 16

Which is the dominant process used in a star with 2.7 solar masses to generate light?

Deuterium fusion.
The CNO cycle.
The proton-proton chain.

Question 17

In an atom, the protons are located...

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

Question 18

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

0.
-1.
+1.

Question 19

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

Question 20

Which of the following stars is the hottest?

K3
K9
K5

Question 21

In the H-R diagram, red dwarfs 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 22

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

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

Question 23

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 24

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 more energy.
3 times less energy.

Question 25

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 planet.
A brown dwarf.
A star.