MSU ISP 205 Final Exam Latest 2026
UPDATED Questions and Verified
Answers (2026/2027) | Graded A+ |
100% Success
What is the source of the Sun's energy? - Correct Answer -Nuclear fusion.
Which of the following statements is an inference from a model (rather than an
observation)? - Correct Answer -The Sun's core is gradually turning hydrogen into
helium.
When the temperature of the Sun's core goes down, what happens next? -
Correct Answer -Fusion reactions slow down, core shrinks and heats.
How do we know how old the Sun is? - Correct Answer -From ages of solar system
meteorites, based on radioactive elements.
Which of the following quantities is equal to the energy per second generated by
the Sun's nuclear reactions? - Correct Answer -the luminosity of the Sun's
photosphere
,Which of the following properties of a star can be measured during a single night
at the telescope? - Correct Answer -apparent brightness
If the distance between us and a star is doubled, with everything else remaining
the same, the luminosity - Correct Answer -remains the same, but the apparent
brightness is decreased by a factor of four.
Which main sequence star has has the lowest mass? - Correct Answer -M
Which star is the hottest star? - Correct Answer -O
If a star has a mass of 10 solar masses and a luminosity of 10,000 solar
luminosities, how long is its lifetime? (The Sun's life time is 10 billion years.) -
Correct Answer -10 million years
How do we estimate the surface temperature of a star? - Correct Answer -By
obtaining its spectrum and classifying the spectral type.
Which star cluster is the youngest star cluster? The one where the brightest main
sequence stars are ... - Correct Answer -O stars
, What property is common to all main sequence stars? - Correct Answer -All are
fusing hydrogen into helium.
Which gas is colder ? - Correct Answer -Molecular hydrogen
Why doesn't a brown dwarf become a star? (Choose the best answer.) - Correct
Answer -It does not have enough mass for its core to start fusion reactions before
degeneracy pressure prevents further collapse.
What is the fate of an isolated brown dwarf? - Correct Answer -It will remain a
brown dwarf forever.
Which of the following sequences correctly describes the stages of life for a low-
mass star? - Correct Answer -protostar, main-sequence, red giant, white dwarf
What does a massive star ends its life as? - Correct Answer -a supernova
Why does the fusion of helium to carbon require a higher temperature and
pressure than the fusion of hydrogen to helium? - Correct Answer -Because the
UPDATED Questions and Verified
Answers (2026/2027) | Graded A+ |
100% Success
What is the source of the Sun's energy? - Correct Answer -Nuclear fusion.
Which of the following statements is an inference from a model (rather than an
observation)? - Correct Answer -The Sun's core is gradually turning hydrogen into
helium.
When the temperature of the Sun's core goes down, what happens next? -
Correct Answer -Fusion reactions slow down, core shrinks and heats.
How do we know how old the Sun is? - Correct Answer -From ages of solar system
meteorites, based on radioactive elements.
Which of the following quantities is equal to the energy per second generated by
the Sun's nuclear reactions? - Correct Answer -the luminosity of the Sun's
photosphere
,Which of the following properties of a star can be measured during a single night
at the telescope? - Correct Answer -apparent brightness
If the distance between us and a star is doubled, with everything else remaining
the same, the luminosity - Correct Answer -remains the same, but the apparent
brightness is decreased by a factor of four.
Which main sequence star has has the lowest mass? - Correct Answer -M
Which star is the hottest star? - Correct Answer -O
If a star has a mass of 10 solar masses and a luminosity of 10,000 solar
luminosities, how long is its lifetime? (The Sun's life time is 10 billion years.) -
Correct Answer -10 million years
How do we estimate the surface temperature of a star? - Correct Answer -By
obtaining its spectrum and classifying the spectral type.
Which star cluster is the youngest star cluster? The one where the brightest main
sequence stars are ... - Correct Answer -O stars
, What property is common to all main sequence stars? - Correct Answer -All are
fusing hydrogen into helium.
Which gas is colder ? - Correct Answer -Molecular hydrogen
Why doesn't a brown dwarf become a star? (Choose the best answer.) - Correct
Answer -It does not have enough mass for its core to start fusion reactions before
degeneracy pressure prevents further collapse.
What is the fate of an isolated brown dwarf? - Correct Answer -It will remain a
brown dwarf forever.
Which of the following sequences correctly describes the stages of life for a low-
mass star? - Correct Answer -protostar, main-sequence, red giant, white dwarf
What does a massive star ends its life as? - Correct Answer -a supernova
Why does the fusion of helium to carbon require a higher temperature and
pressure than the fusion of hydrogen to helium? - Correct Answer -Because the
