Astro 5 Kudu UPDATED ACTUAL Exam
Questions and CORRECT Answers
How has the universe changed as it has moved forward in time? - CORRECT ANSWER -
It has become cooler and less dense
How might fundamental forces (gravity, the weak force, the strong force) be affected by
extremely high temperatures? - CORRECT ANSWER - They become the same force
What was the approximate mass composition of the universe just before stars began to form? -
CORRECT ANSWER - 75% hydrogen and 25% helium
What is surprising about the universe from the period observed using the cosmic microwave
background? - CORRECT ANSWER - The universe was smoother than expected
What is the earliest time in the universe that we have a fairly strong understanding of? -
CORRECT ANSWER - 10^-27s after the big bang
What occurred about 380,000 years after the big bang? - CORRECT ANSWER - Electrons
merged with nuclei to form atoms
About how long after the big bang were protons and neutrons able to merge together into nuclei?
- CORRECT ANSWER - 3 minutes
How did the horizon of the visible universe in the early universe compare to that which we have
today? - CORRECT ANSWER - The horizon was smaller and got larger as time went on
When talking about the early stages of the universe what does inflation refer to? - CORRECT
ANSWER - A period of rapid expansion of the universe soon after the big bang.
, What is thought to be the cause of temperature variations in the cosmic microwave background?
- CORRECT ANSWER - Tiny quantum fluctuations in the early universe expanded to a
macroscopic size by inflation.
Light is a radiant form of energy that travels through space in the form of fluctuating -
CORRECT ANSWER - Electric and magnetic fields
In the equation E\propto \frac{1}{\lambda}E∝λ1 , what does E refer to? - CORRECT
ANSWER - The energy of an individual photon of light
Humans can see the difference in certain wavelengths of light in the form of... - CORRECT
ANSWER - Color
When we see light it sometimes appears to be a longer or shorter wavelength than it was emitted
at, this is a result of what? - CORRECT ANSWER - Doppler shifting
How do we determine the type of an atom? (hydrogen, helium, gold, etc.) - CORRECT
ANSWER - The number of protons in the atom
What must be true of a photon in order for it to interact with the electrons of an atom? -
CORRECT ANSWER - It must have exactly the right amount of energy to take the
electron to another energy level
How does an absorption spectrum differ from an emission spectrum? - CORRECT
ANSWER - An absorption spectrum shows as a pattern of dark lines against a continuous
spectrum whereas an emission spectrum is a pattern of bright lines against a dark background.
The precise pattern of wavelengths in an absorption or emission spectrum is ___________ -
CORRECT ANSWER - a signature of the types of atoms in the object
When light has been redshifted that means that it has... - CORRECT ANSWER - Had its
wavelength increased due to motion away from us
Questions and CORRECT Answers
How has the universe changed as it has moved forward in time? - CORRECT ANSWER -
It has become cooler and less dense
How might fundamental forces (gravity, the weak force, the strong force) be affected by
extremely high temperatures? - CORRECT ANSWER - They become the same force
What was the approximate mass composition of the universe just before stars began to form? -
CORRECT ANSWER - 75% hydrogen and 25% helium
What is surprising about the universe from the period observed using the cosmic microwave
background? - CORRECT ANSWER - The universe was smoother than expected
What is the earliest time in the universe that we have a fairly strong understanding of? -
CORRECT ANSWER - 10^-27s after the big bang
What occurred about 380,000 years after the big bang? - CORRECT ANSWER - Electrons
merged with nuclei to form atoms
About how long after the big bang were protons and neutrons able to merge together into nuclei?
- CORRECT ANSWER - 3 minutes
How did the horizon of the visible universe in the early universe compare to that which we have
today? - CORRECT ANSWER - The horizon was smaller and got larger as time went on
When talking about the early stages of the universe what does inflation refer to? - CORRECT
ANSWER - A period of rapid expansion of the universe soon after the big bang.
, What is thought to be the cause of temperature variations in the cosmic microwave background?
- CORRECT ANSWER - Tiny quantum fluctuations in the early universe expanded to a
macroscopic size by inflation.
Light is a radiant form of energy that travels through space in the form of fluctuating -
CORRECT ANSWER - Electric and magnetic fields
In the equation E\propto \frac{1}{\lambda}E∝λ1 , what does E refer to? - CORRECT
ANSWER - The energy of an individual photon of light
Humans can see the difference in certain wavelengths of light in the form of... - CORRECT
ANSWER - Color
When we see light it sometimes appears to be a longer or shorter wavelength than it was emitted
at, this is a result of what? - CORRECT ANSWER - Doppler shifting
How do we determine the type of an atom? (hydrogen, helium, gold, etc.) - CORRECT
ANSWER - The number of protons in the atom
What must be true of a photon in order for it to interact with the electrons of an atom? -
CORRECT ANSWER - It must have exactly the right amount of energy to take the
electron to another energy level
How does an absorption spectrum differ from an emission spectrum? - CORRECT
ANSWER - An absorption spectrum shows as a pattern of dark lines against a continuous
spectrum whereas an emission spectrum is a pattern of bright lines against a dark background.
The precise pattern of wavelengths in an absorption or emission spectrum is ___________ -
CORRECT ANSWER - a signature of the types of atoms in the object
When light has been redshifted that means that it has... - CORRECT ANSWER - Had its
wavelength increased due to motion away from us
