# E1 Astrophysics E1 - E2.4

Approved & Edited by ProProfs Editorial Team
The editorial team at ProProfs Quizzes consists of a select group of subject experts, trivia writers, and quiz masters who have authored over 10,000 quizzes taken by more than 100 million users. This team includes our in-house seasoned quiz moderators and subject matter experts. Our editorial experts, spread across the world, are rigorously trained using our comprehensive guidelines to ensure that you receive the highest quality quizzes.
| By Gboulton
G
Gboulton
Community Contributor
Quizzes Created: 18 | Total Attempts: 9,709
Questions: 9 | Attempts: 808

Settings

Introduction to Astrophysics.

• 1.

### What are comets made of?

• A.

Sugar and spice and all things nice?

• B.

Slugs and snails and puppy dogs' tails

• C.

Frozen ice and carbon dioxide, hydrogen and helium

• D.

Frozen ice and carbon dioxide, methane and ammonia

• E.

Hydrogen, helium, methane and ammonia

D. Frozen ice and carbon dioxide, methane and ammonia
Explanation
Comets are made of frozen ice, such as water ice, and various gases, including carbon dioxide, methane, and ammonia. These substances make up the nucleus of a comet. As a comet approaches the Sun, the heat causes the ice to vaporize, creating a glowing coma around the nucleus and forming a tail. The presence of these gases in comets is important for studying the composition and evolution of the solar system.

Rate this question:

• 2.

### Define a light year.

• A.

The time it takes light to travel for a year.

• B.

The distance light travels in a year.

• C.

Time between starting and finishing when light travels through space

• D.

None of the above

B. The distance light travels in a year.
Explanation
A light year is a unit of measurement used in astronomy to describe the distance that light travels in one year. It is not a measure of time, as stated in the other options. The speed of light is approximately 299,792,458 meters per second, so in one year, light can travel about 9.461 trillion kilometers. This distance is used to understand the vastness of the universe and to measure astronomical distances.

Rate this question:

• 3.

### What is the diameter of our galaxy

• A.

100 LY

• B.

1,000 LY

• C.

10,000 LY

• D.

100,000 LY

• E.

1,000,000 LY

D. 100,000 LY
Explanation
The correct answer is 100,000 LY. The diameter of our galaxy, the Milky Way, is estimated to be around 100,000 light-years. This means that if you were to travel at the speed of light, it would take you 100,000 years to traverse the entire diameter of the galaxy.

Rate this question:

• 4.

### What are the largest gravitationally bound structures?

• A.

Solar system,

• B.

Galaxy

• C.

Stellar cluster

• D.

Galaxy cluster

• E.

Super cluster

D. Galaxy cluster
Explanation
Galaxy clusters are the largest gravitationally bound structures in the universe. They consist of hundreds to thousands of galaxies held together by their mutual gravitational attraction. These clusters are enormous in size, spanning millions of light-years across. The gravitational force between the galaxies keeps them bound within the cluster, and the immense mass of these clusters influences the formation and evolution of galaxies within them.

Rate this question:

• 5.

### What apparent effect is caused by the rotation of the earth on its axis?

• A.

Stars move around pole star

• B.

Sun moves into different constellations during the year

• C.

Stellar parallax

• D.

A. Stars move around pole star
Explanation
The rotation of the earth on its axis causes the apparent effect of stars moving around the pole star. As the earth rotates, it gives the illusion that the stars are moving in a circular motion around the pole star, which is located near the North Celestial Pole. This phenomenon is known as the diurnal motion of the stars and is caused by the earth's rotation.

Rate this question:

• 6.

### What provides the radiant energy for most stars?

• A.

Hydrogen combustion in core

• B.

Hydrogen combustion in shell.

• C.

Hydrogen fusion in core.

• D.

Hydrogen fusion in shell.

C. Hydrogen fusion in core.
Explanation
Hydrogen fusion in the core is the correct answer because it is the process by which stars generate energy. In the core of a star, hydrogen atoms combine to form helium through nuclear fusion. This fusion reaction releases a tremendous amount of energy in the form of radiant energy, which is what provides the heat and light of the star. Hydrogen combustion in the core or shell, as well as hydrogen fusion in the shell, are not accurate explanations for the energy source of most stars.

Rate this question:

• 7.

### What is the most important thing about a start which determines pretty much everything about it?

• A.

Temperature

• B.

Luminosity

• C.

Mass

• D.

Age

• E.

Life expectancy

C. Mass
Explanation
The most important thing about a star that determines pretty much everything about it is its mass. The mass of a star determines its temperature, luminosity, age, and even its life expectancy. The mass of a star influences the rate of nuclear reactions happening in its core, which in turn determines its temperature and luminosity. Additionally, a star's mass affects its lifespan, with more massive stars having shorter lifespans compared to less massive ones. Therefore, the mass of a star plays a crucial role in shaping its characteristics and overall behavior.

Rate this question:

• 8.

### What happens to the luminosity if you compare with a start which has twice the mass (what will be the luminosity of the larger star)?

• A.

The luminosity will be half as big.

• B.

The luminosity will be the same.

• C.

The luminosity will be twice as much.

• D.

The luminosity will be 3x as much.

• E.

The luminosity will be 4x as much.

• F.

The luminosity will be 8x as much.

F. The luminosity will be 8x as much.
Explanation
When comparing two stars, the luminosity is directly proportional to the mass of the star raised to the power of 3. Therefore, if a star has twice the mass of another star, its luminosity will be 2^3 = 8 times greater.

Rate this question:

• 9.

### Are there any parts of this topic so far that you find difficult?

Quiz Review Timeline +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

• Current Version
• Mar 20, 2023
Quiz Edited by
ProProfs Editorial Team
• Jan 13, 2013
Quiz Created by
Gboulton

Related Topics