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

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

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

Question 2

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

Question 3

Which of the following is the shortest?

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

Question 4

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 5

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

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

Question 6

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.

Question 7

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

0.
-1.
+1.

Question 8

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

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

Question 9

Which of the following stars is the coolest?

K5
K9
K3

Question 10

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

7
8
6

Question 11

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

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

Question 12

Which of the following is a main-sequence star?

K6 V
G2 IV
B5 II

Question 13

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

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

Question 14

Which of the following is a red dwarf?

G2 V
M5 V
O4 III

Question 15

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
Stellar parallax
Cepheid variables

Question 16

A star is located on the top left of the H-R diagram. This star has...

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

Question 17

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 18

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

Red.
Green.
Blue.

Question 19

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 20

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 21

In an atom, the electrons are located...

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

Question 22

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 23

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 brown dwarf.
A star.
A planet.

Question 24

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 25

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.
9 times more energy.
3 times more energy.