PSU Astro 7N Exam 1 Questions and
Answers
What two properties of a planet affect the gravity we feel on its surface?
✓ ~~~Mass and radius
Two planets have the same radius. If Planet A is 5 times more mass than Planet B,
how does gravity differ on the surfaces of the two planets?
✓ ~~~Gravity is 5 times stronger on planet A
Say that there were a planet X in our Solar System with a mass 1/4 the mass of
Earth and a radius 1/2 the radius of Earth. How will the gravity on its surface
compare to the surface gravity of Earth?
✓ ~~~Surface gravity on planet X is the same as on earth
A planet in a nearly circular orbit with its rotation axis tilted by 5 degrees relative to
its orbital plane around its star would ...
✓ ~~~Have seasons that are not very different from each other as compared to Earth
The rotation axis of the Earth is ...
✓ ~~~Tilted at about 23 degrees relative to the axis of the Earth's orbit around the Sun
In the diagram above, what season and planet is being represented by the red X on
the planet on the left in orbit around the Sun?
✓ ~~~
,When is the waning gibbous moon highest in the sky?
✓ ~~~About 3 am
What phase is the Moon in, when observed by the person standing on the Earth in
the diagram above?
✓ ~~~New
At what time will the Moon set on the day of a Solar eclipse?
✓ ~~~Sunset
Stars that are in the same constellation ...
✓ ~~~are likely to be at very different distances from us.
The "North Star" is a star in the constellation of Ursa Minor, which lies just above the
North pole of Earth. Which of the following is true?
✓ ~~~Ursa Minor is a Zodiac constellation in the summer but not in the winter
A particular Zodiac constellation is high in the sky at midnight in April. Where will it
be in October?
✓ ~~~Near the Sun in the daytime sky
What do you expect the spectrum of an object that is 1,000,000 Kelvin to be like?
✓ ~~~It should peak at X-ray wavelengths
As compared to a cool star, a hotter star emits ...
, ✓ ~~~Shorter wavelength, higher frequency, bluer color
Radio waves can travel large distances without interference because ...
✓ ~~~They have longer wavelengths than visible light
Compared to ultraviolet radiation, X-rays have a wavelength that is ...
✓ ~~~Shorter
Star A is 4000 K, and Star B is 8000 K. Which of the following is true?
✓ ~~~The color of Star A is redder than Star B
In the diagram above, what is happening in the box in the center?
✓ ~~~
A star is a hot, dense gas surrounded by a cooler, low density atmosphere. What
type of spectrum will a star create?
✓ ~~~Absorption Spectrum
What makes a transition from a lower energy state to a higher energy state when a
photon is absorbed into an atom?
✓ ~~~Electron
An emission line is produced when:
✓ ~~~An electron passes from a higher to a lower energy level
Bright lines in an emission spectrum represent:
Answers
What two properties of a planet affect the gravity we feel on its surface?
✓ ~~~Mass and radius
Two planets have the same radius. If Planet A is 5 times more mass than Planet B,
how does gravity differ on the surfaces of the two planets?
✓ ~~~Gravity is 5 times stronger on planet A
Say that there were a planet X in our Solar System with a mass 1/4 the mass of
Earth and a radius 1/2 the radius of Earth. How will the gravity on its surface
compare to the surface gravity of Earth?
✓ ~~~Surface gravity on planet X is the same as on earth
A planet in a nearly circular orbit with its rotation axis tilted by 5 degrees relative to
its orbital plane around its star would ...
✓ ~~~Have seasons that are not very different from each other as compared to Earth
The rotation axis of the Earth is ...
✓ ~~~Tilted at about 23 degrees relative to the axis of the Earth's orbit around the Sun
In the diagram above, what season and planet is being represented by the red X on
the planet on the left in orbit around the Sun?
✓ ~~~
,When is the waning gibbous moon highest in the sky?
✓ ~~~About 3 am
What phase is the Moon in, when observed by the person standing on the Earth in
the diagram above?
✓ ~~~New
At what time will the Moon set on the day of a Solar eclipse?
✓ ~~~Sunset
Stars that are in the same constellation ...
✓ ~~~are likely to be at very different distances from us.
The "North Star" is a star in the constellation of Ursa Minor, which lies just above the
North pole of Earth. Which of the following is true?
✓ ~~~Ursa Minor is a Zodiac constellation in the summer but not in the winter
A particular Zodiac constellation is high in the sky at midnight in April. Where will it
be in October?
✓ ~~~Near the Sun in the daytime sky
What do you expect the spectrum of an object that is 1,000,000 Kelvin to be like?
✓ ~~~It should peak at X-ray wavelengths
As compared to a cool star, a hotter star emits ...
, ✓ ~~~Shorter wavelength, higher frequency, bluer color
Radio waves can travel large distances without interference because ...
✓ ~~~They have longer wavelengths than visible light
Compared to ultraviolet radiation, X-rays have a wavelength that is ...
✓ ~~~Shorter
Star A is 4000 K, and Star B is 8000 K. Which of the following is true?
✓ ~~~The color of Star A is redder than Star B
In the diagram above, what is happening in the box in the center?
✓ ~~~
A star is a hot, dense gas surrounded by a cooler, low density atmosphere. What
type of spectrum will a star create?
✓ ~~~Absorption Spectrum
What makes a transition from a lower energy state to a higher energy state when a
photon is absorbed into an atom?
✓ ~~~Electron
An emission line is produced when:
✓ ~~~An electron passes from a higher to a lower energy level
Bright lines in an emission spectrum represent:
