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

5 parsecs.
4 parsecs.
6 parsecs.

Question 2

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

8
7
6

Question 3

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

1.
2.
4.

Question 4

Which of the following is a main-sequence star?

B5 II
G2 IV
K6 V

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

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

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

Question 7

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

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

Question 8

Which of the following is a blue giant?

M2 III
M5 V
O4 III

Question 9

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 10

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 11

Object A has mass 1 kg. Object B has mass 3 kg. According to E=mc², how much rest energy does object B have compared to A?

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

Question 12

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 13

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

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

Question 14

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 15

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

Question 16

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

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

Question 17

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

Blue.
Red.
Green.

Question 18

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 19

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

-1.
+1.
0.

Question 20

Which of the following stars is the hottest?

K3
K9
K5

Question 21

In an atom, the protons are located...

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

Question 22

I see a very faint 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 23

Which of the following is the shortest?

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

Question 24

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 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 star.
A brown dwarf.