Question

Question 8 (1 point)

The main sequence turn-off of a cluster of stars is a good indicator of which of the following properties of the cluster?

Question 8 options:

	age
	number of stars in the cluster
	chemical composition
	distance

Saved

Which of the following is key difference between the pressure in a normal gas and in a degenerate gas?

Question 9 options:

	in a degenerate gas, pressure doesn't depend on temperature
	in a degenerate gas, pressure doesn't depend on density
	degenerate pressure exists whether matter is present or not
	in a degenerate gas pressure varies rapidly with time

Question 10 (1 point)

Saved

Stars like the Sun probably do not form iron cores during their evolution because

Question 10 options:

	all the iron is ejected when they become planetary nebulas.
	their cores never get hot enough for them to make iron by nucleosynthesis.
	the iron they make by nucleosynthesis is all fused into uranium.
	their strong magnetic fields keep their iron in their atmospheres
	None of the above

Saved

The difference between the apparent and absolute magnitudes of a star is a measure of the star's

Question 12 options:

	luminosity
	temperature
	brightness as we perceive it
	distance

Answer 1

Question -8 - option (a) is correct. The main sequence turn-off of a cluster of stars is a good indicator of age of stars

Question -9 - option (a) is correct. The  degeneracy pressure does not depend on the temperature but only on the density of the fermions.

Question - 10 - option (b) is correct. Their cores never get hot enough for them to make iron by nucleosynthesis.

Question - 12- option (c) is correct . Brightness is main difference