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

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

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

Question 2

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

6 parsecs.
4 parsecs.
5 parsecs.

Question 3

Which of the following is a blue giant?

M2 III
M5 V
O4 III

Question 4

A proton 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

In an atom, the electrons are located...

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

Question 6

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 7

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 8

Which of the following is the longest?

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

Question 9

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 10

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 A is more luminous.
Star B is more luminous.

Question 11

What happens in electron-positron annihilation?

An electron and a positron annihilate each other and produce 1 photon.
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.

Question 12

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

Blue.
Red.
Green.

Question 13

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 14

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

7
8
6

Question 15

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

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

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
Cepheid variables
Stellar parallax

Question 17

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 18

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

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

Question 19

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 20

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 21

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

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

Question 22

Which of the following is a main-sequence star?

G2 IV
K6 V
B5 II

Question 23

Which of the following stars is the hottest?

K3
K9
K5

Question 24

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

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

Question 25

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

-1.
+1.
0.