The design of modern X-ray telescopes depends on A) lenses ...

[Metfan725]

The design of modern X-ray telescopes depends on
 
  A) lenses made of germanium.
  B) the prime focus design, with mirrors made of iron.
  C) grazing incidence optics.
  D) achromatic lenses to keep the X-rays in focus.
  E) the Cassegrain design, with mirrors made of lead.

Question 2

Which is brighter in our sky, a star with apparent magnitude 2 or a star with apparent magnitude 7? By how much is the star brighter?
 
  What will be an ideal response?

[popopong]

Answer to Question 1

C

Answer to Question 2

A star with apparent magnitude 2 is 100 times brighter than a star with apparent magnitude 7. (Five magnitudes indicates a factor-of-100 difference; larger apparent magnitude stars are always fainter.)

[Metfan725]

Both answers were spot on, thank you once again

[popopong]

Great! Please up vote