PHYS 284 Midterm Exam all done solution Concordia University
+ Instructions
Which of the following is always true about images captured with X-ray Points: 0.5
1 telescopes?
They are always shown with colours that are not the true colours of the
✓
objects that were photographed.
B They always are made with adaptive optics.
They show us light with extremely long wavelengths compared to the
C
wavelengths of visible light.
D They always have very high angular resolution.
E They are always very pretty.
Which of the following telescopes would benefit most from adaptive Points: 0.5
2 optics?
✓ The Keck I Telescope on Mauna Kea.
, B The Hubble Space Telescope.
C The Arecibo Radio Telescope in Puerto Rico.
D The Chandra X-Ray Observatory.
Consider two future observatories in space. Observatory X consists ofa single Points: 0.5
3 50-metre telescope. Observatory Y is an interferometre
consisting of five 10-metre telescopes, spread out over a region 100metres
across. Which observatory can detect dimmer stars, and which one can
see more detail in its images? (Assume all else is
equal, such as quality of optics, types of instruments, and so on.)
Observatory X can detect dimmer stars and Observatory Y reveals moredetail
✓
in images.
Observatory Y can detect dimmer stars and Observatory X reveals moredetail
B
in images.
Observatory X both detects dimmer stars and reveals more detail in
C
images.
Observatory Y both detects dimmer stars and reveals more detail in
D
images.
How does looking at light from distant objects help us predict the Points: 0.5
4 temperature of the object?
The light spectrum of the distant object tells us what the object is madeof and
✓
therefore tells us its temperature.
B The shape of the object's continuous spectrum tells us its temperature.
, We can infer the temperature of the object by comparing the spectrum ofthe
C
object's light with a laboratory spectrum of lines at rest.
By estimating the Doppler shift of the object, we can estimate its
D
temperature.
Which of these is more likely to produce an emission line spectrumover a Points: 0.5
5 continous spectrum?
A A solid material
B A material with very closely-spaced energy levels
C A cold gas containing only one type of atom
D A cold solid material containing only one type of atom
E A heated wire filament
✓ A star
G A planet
What do both light waves and sound waves have in common? Points: 0.5
6
✓ They can both be Doppler shifted.
B They are both electromagnetic waves.
+ Instructions
Which of the following is always true about images captured with X-ray Points: 0.5
1 telescopes?
They are always shown with colours that are not the true colours of the
✓
objects that were photographed.
B They always are made with adaptive optics.
They show us light with extremely long wavelengths compared to the
C
wavelengths of visible light.
D They always have very high angular resolution.
E They are always very pretty.
Which of the following telescopes would benefit most from adaptive Points: 0.5
2 optics?
✓ The Keck I Telescope on Mauna Kea.
, B The Hubble Space Telescope.
C The Arecibo Radio Telescope in Puerto Rico.
D The Chandra X-Ray Observatory.
Consider two future observatories in space. Observatory X consists ofa single Points: 0.5
3 50-metre telescope. Observatory Y is an interferometre
consisting of five 10-metre telescopes, spread out over a region 100metres
across. Which observatory can detect dimmer stars, and which one can
see more detail in its images? (Assume all else is
equal, such as quality of optics, types of instruments, and so on.)
Observatory X can detect dimmer stars and Observatory Y reveals moredetail
✓
in images.
Observatory Y can detect dimmer stars and Observatory X reveals moredetail
B
in images.
Observatory X both detects dimmer stars and reveals more detail in
C
images.
Observatory Y both detects dimmer stars and reveals more detail in
D
images.
How does looking at light from distant objects help us predict the Points: 0.5
4 temperature of the object?
The light spectrum of the distant object tells us what the object is madeof and
✓
therefore tells us its temperature.
B The shape of the object's continuous spectrum tells us its temperature.
, We can infer the temperature of the object by comparing the spectrum ofthe
C
object's light with a laboratory spectrum of lines at rest.
By estimating the Doppler shift of the object, we can estimate its
D
temperature.
Which of these is more likely to produce an emission line spectrumover a Points: 0.5
5 continous spectrum?
A A solid material
B A material with very closely-spaced energy levels
C A cold gas containing only one type of atom
D A cold solid material containing only one type of atom
E A heated wire filament
✓ A star
G A planet
What do both light waves and sound waves have in common? Points: 0.5
6
✓ They can both be Doppler shifted.
B They are both electromagnetic waves.
