Astr 121 Exam 1 Flashcards Set (Ultimate)

Multiple Choice Exam: Astronomy Concepts

1. Distance Scales & Scientific Notation

1.1 What is the scientific notation of 1,232,000,000?
a) 1.232 × 10⁹
b) 1.232 × 10⁶
c) 12.32 × 10⁹
d) 1.23 × 10¹⁰

1.2 Which of the following represents 0.00000453 in scientific notation?
a) 4.53 × 10⁶
b) 4.53 × 10⁻⁶
c) 4.53 × 10⁻³
d) 4.53 × 10⁻⁹

1.3 Which of these is the correct prefix for one million?
a) kilo
b) mega
c) giga
d) nano

1.4 What is the value of one astronomical unit (A.U.)?
a) 150 million kilometers
b) 300 million kilometers
c) 1 million kilometers
d) 93 million kilometers

1.5 What is the main way we see history in astronomy?
a) The light from stars takes time to travel to Earth, so we see them as they were in the past.
b) Astronomers measure the past through historical records of star positions.
c) Telescopes are time machines that view the future.
d) The Earth’s atmosphere distorts our view, creating a historical image.

2. The Scientific Method

2.1 Which of the following is the correct order of steps in the scientific method?
a) Observation, hypothesis, experiment, conclusion
b) Hypothesis, observation, conclusion, experiment
c) Observation, conclusion, hypothesis, experiment
d) Experiment, observation, hypothesis, conclusion

2.2 What is the difference between a hypothesis and a theory?
a) A theory is a testable prediction, while a hypothesis is a general principle.
b) A hypothesis is based on empirical data, while a theory is based on guesses.
c) A theory has been proven by experiments, while a hypothesis is a proposed explanation.
d) A theory is something that can be proven, while a hypothesis cannot.

2.3 Which of these is an example of a pseudoscientific argument?
a) Using statistical data to make predictions
b) Relying on anecdotal evidence without supporting experiments
c) Peer-reviewed research published in scientific journals
d) Controlled experiments that can be repeated for validation

3. Motions in the Sky

3.1 What is the term for the apparent size of an object in the sky?
a) Angular separation
b) Altitude
c) Angular size
d) Right ascension

3.2 Which star is located directly above Earth's north pole?
a) Sirius
b) Polaris
c) Vega
d) Alpha Centauri

3.3 What does the term "circumpolar" mean?
a) Stars that never rise
b) Stars that are visible from the equator
c) Stars that never set at a particular latitude
d) Stars that rise and set at regular intervals

3.4 The celestial equator divides the sky into what two hemispheres?
a) Northern and Southern
b) Right Ascension and Declination
c) Zenith and Horizon
d) Day and Night

4. Planetary Laws

4.1 What did Tycho Brahe contribute to Kepler’s work?
a) Mathematical equations for planetary motion
b) Accurate data on planetary positions
c) Discovery of Kepler's third law
d) The theory of heliocentrism

4.2 What is Kepler’s second law of planetary motion?
a) Planets move in elliptical orbits with the Sun at one focus
b) The square of a planet's orbital period is proportional to the cube of its semi-major axis
c) Planets sweep out equal areas in equal times
d) Planets move in perfect circles around the Sun

4.3 If a planet is 100 A.U. away from the Sun, what is its orbital period?
a) 100 years
b) 10 years
c) 1 year
d) 1000 years

5. Newton’s Laws & Gravity

5.1 What is the difference between weight and mass?
a) Mass measures the amount of matter; weight is the force of gravity on that mass.
b) Mass is a force; weight is the amount of matter.
c) Weight is constant; mass varies with gravity.
d) Mass is only relevant in space; weight applies only on Earth.

5.2 What is Newton's law of gravitation?
a) The force of gravity between two objects is directly proportional to the square of the distance between them.
b) The force of gravity between two objects is inversely proportional to the square of the distance between them.
c) The force of gravity between two objects is directly proportional to the mass of one object only.
d) Gravity is a force that exists only between objects with the same mass.

5.3 If you triple the distance between the Earth and the Sun, what happens to the gravitational force between them?
a) It decreases by a factor of 3.
b) It decreases by a factor of 9.
c) It increases by a factor of 3.
d) It remains the same.

6. The Nature of Light

6.1 What did Galileo attempt to do in order to measure the speed of light?
a) Use a rotating mirror
b) Observe light through a telescope
c) Measure the time light took to travel across the Earth
d) Use the distance between Earth and the Moon

6.2 What is the electromagnetic spectrum?
a) The range of all radio frequencies
b) The range of all visible colors of light
c) The entire range of frequencies of electromagnetic radiation
d) A method to measure the speed of light

6.3 What is the speed of light?
a) 3 x 10⁸ meters per second
b) 3 x 10¹² meters per second
c) 2 x 10⁸ meters per second
d) 1 x 10⁸ meters per second

7. Generation of Light

7.1 What causes an electron to transition to a higher energy level?
a) Absorption of a photon
b) Emission of a photon
c) Collision with another atom
d) Loss of energy

7.2 What is a black body spectrum?
a) A spectrum emitted by a glowing solid object
b) A spectrum of light absorbed by a material
c) A spectrum emitted by cold gases
d) A spectrum from a non-luminous object

7.3 Which law describes the relationship between the temperature of a body and the peak wavelength of its emission?
a) Stefan-Boltzmann Law
b) Wien's Law
c) Ohm's Law
d) Newton’s Law

8. Telescopes

8.1 What is the most important property of a telescope?
a) Magnification
b) Light-gathering ability
c) Size of the eyepiece
d) Type of mirror

8.2 What type of telescope do most modern astronomers use?
a) Refracting telescopes
b) Reflecting telescopes
c) Radio telescopes
d) X-ray telescopes

8.3 How does the area of a telescope's objective lens or mirror relate to its light-gathering power?
a) It is proportional to the square of the diameter.
b) It is proportional to the diameter.
c) It is inversely proportional to the diameter.
d) It is unrelated to the diameter.

9. Astronomical Instrumentation

9.1 What is the function of a spectrograph in astronomy?
a) Measure the distance to stars
b) Record and analyze light from astronomical objects
c) Adjust the focus of a telescope
d) Capture images of distant planets

9.2 Why do astronomers use CCD cameras instead of photographic plates?
a) They provide better resolution and can store data electronically.
b) They are less expensive and easier to use.
c) They collect data faster but with less detail.
d) They are more sensitive to X-rays than plates.

9.3 What is adaptive optics used for?
a) To increase the resolution of telescopes by compensating for atmospheric distortion
b) To filter out harmful radiation
c) To track the movement of stars
d) To increase magnification

10. The Sun’s Atmosphere

10.1 What is the composition of the Sun?
a) Mostly hydrogen and helium
b) Oxygen and nitrogen
c) Carbon dioxide and nitrogen
d) Iron and nickel

10.2 What are sunspots?
a) Areas of intense heat on the Sun
b) Cooler areas caused by magnetic activity
c) The hottest part of the Sun
d) Solar flares

10.3 How does solar activity affect Earth?
a) It causes solar winds that may impact satellites and communication systems.
b) It causes the Earth to heat up.
c) It has no effect on Earth.
d) It causes Earth’s orbit to change.

11. The Sun’s Interior

11.1 What is thermonuclear fusion?
a) The process by which stars produce light through chemical reactions
b) The process by which atoms split apart to release energy
c) The process by which nuclei combine to release energy
d) The process by which stars cool down and shrink

11.2 How long does it take for photons created in the Sun’s core to reach its surface?
a) A few minutes
b) A few years
c) Several hundred thousand years
d) A few days

11.3 What is the solar neutrino problem?
a) The mystery of why neutrinos are not detected
b) The discrepancy in the number of neutrinos detected from the Sun
c) The high-energy neutrinos coming from distant stars
d) The theory that neutrinos travel faster than light

End of Exam