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

What happens to the mass in electron-positron annihilation?

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

Question 2

In an atom, the protons are located...

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

Question 3

A photon has a wavelength of 700 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

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

-1.
0.
+1.

Question 6

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 7

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 8

Star A has brighter apparent 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 9

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 10

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

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

Question 11

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

4 parsecs.
6 parsecs.
5 parsecs.

Question 12

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 13

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

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

Question 14

If the spectral lines of a star shift toward blue, this means...

The star is moving away from us.
The star is not moving with respect to us.
The star is moving toward us.

Question 15

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

Question 16

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!)

4.
2.
1.

Question 17

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

6
7
8

Question 18

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.

Question 19

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 20

Which of the following is a bright giant?

G2 IV
B5 II
K6 V

Question 21

Which of the following is a blue giant?

M2 III
O4 III
M5 V

Question 22

Which of the following stars is the hottest?

K5
K9
K3

Question 23

What is nuclear fusion?

The process where heavy nuclei split into lighter nuclei.
The process where light nuclei combine into heavier nuclei.
The process where nuclei are destroyed and converted into pure energy.

Question 24

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 25

A proton is made of...

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