Exploring the Cosmos - Class Test 1 - Complete B
1. How did Johan Bayer name the stars in the sky? He named them
in the order he found them.
in terms of their co-ordinates in the sky.
based on their colour.
in terms of their relative brightness within constellations.
2. If a star's annular parallax is 0.4, what is the distance?
2.5 AU
2.5 Mpc
2.5 pc
2.5 LY
3. The surface temperature of our Sun is roughly
3,000 K
60,000 K
30,000 K
6,000 K
4. Two isotopes of the same chemical have the same number of what in their nuclei?
neutrons
protons
electrons
photons
5. Which of the following types of stars are most abundant in the universe?
Red dwarfs
Blue giants
Red giants
White dwarfs
6. At roughly what distance is the nearest star to our own?
4.3 parsecs
43 lightyears
4.3 lightyears
43 parsecs
7. Which process allows for the building up of elements heavier than iron?
Helium capture.
Neutron capture.
The alpha-process.
Photodisintegration.
8. What is the name given to the process by which elements are formed in stars?
Stellar manipulation
Stellar construction
Stellar photosynthesis
Stellar nucleosynthesis
9. Which of the following regions of our Sun is the hottest?
Convection zone
Photosphere
Corona
Chromosphere
10. What temperature range do Main Sequence stars fall into?
30 K to 300 K
300 K to 3,000 K
30,000 K to 300,000 K
3,000 K to 30,000 K
11. Roughly how many stars are there in our own galaxy?
100 million
100 billion
1 billion
1 million
12. A hydrogen nucleus contains how many protons?
3
1
4
2
13. Which of the following parameters is the same for all electromagnetic waves propagating in a vacuum?
Wavelength
Speed
Amplitude
Colour
14. Why does a light ray bend when it crosses the boundary between two different media at an oblique angle?
Because the frequency increases.
Because the speed of light changes.
Because it interferes with the surface.
Because the amplitude is reduced.
15. A spectrograph orders electromagnetic waves with respect to which of the following?
Their source.
Their amplitude.
The number of photons in the waves.
Their wavelength.
16. Diffraction gratings are used to
reduce diffraction of telescopes.
increase the resolution of telescopes.
break up light into a spectrum.
detect infrared radiation.
17. The focal length of an ideal mirror depends on the
curvature of the mirror.
colour of the incident light.
diameter of the mirror.
thickness of the mirror.
18. If the width of the objective of a telescope is doubled, what happens to its light gathering power?
The light gathering power increased by a factor of four.
The light gathering power remains the same.
The light gathering power is increased by a factor of two.
The light gathering power is decreased by a factor of four.
19. How old is the universe?
The universe is infinitely old.
About 50 billion years.
About 6 thousand years.
About 14 billion years.
20. The sky is dark at night because
the universe is only sparsely populated with stars.
there is dark matter in between the stars.
the universe is so young that light from faraway stars has not yet reached us.
our eyes are not sensitive enough.
21. What is the observable universe?
Parts of the universe that the most powerful telescopes can resolve.
The portion of the universe from which light had enough time to travel to us.
The portion of the universe that our eyes can see.
All parts of the universe that are not obscured by celestial objects.
22. Ptolemy believed that
everything must move along one simple perfect circle.
all the stars were on a celestial sphere.
some of the planets orbit around the Sun.
Newton was the greatest scientist of all time.
23. Einstein's special theory of relativity implies that
nothing is relative.
all motion is relative to the centre of the universe.
everything is relative.
nothing can travel faster than the speed of light.
24. Kepler's Laws show that
there is no special centre around which the universe rotates.
planetary orbits are elliptical.
a planet orbits the sun with constant speed.
planets cannot be more massive than the star around which they orbit.
25. Globular clusters are usually found in the
halos of galaxies and contain population I stars.
discs of galaxies and contain population I stars.
halos of galaxies and contain population II stars.
discs of galaxies and contain population II stars.
26. Our Sun is situated in
a globular cluster in the galactic disc about half of its radius from the centre.
a globular cluster in the halo of the galaxy.
the disc of the galaxy about two thirds of its radius from the centre.
the disc of the galaxy close to the edge of the disc.
27. Neutral hydrogen can be detected by astronomers because it
reflects blue light from nearby stars.
glows with a bright blue colour.
forms dark clouds in the disc of a spiral galaxy.
radiates a sharp 21 cm radio signal.
28. The approximate position of the centre of the Milky Way galaxy was first found, using optical telescopes, by
measuring the position of visible globular clusters.
measuring the position of visible open star clusters.
looking for the central bulge.
observing stars moving round the massive black hole in the centre.
29. The diameter of the Milky Way Galaxy is about
25 to 30 kpc.
250 to 300 pc.
25 to 30 Mpc.
25 to 30 pc.
30. Of the stars in a spiral galaxy,
those in the spherical component move in circular orbits with random orientations around the galactic centre.
all the stars in the disk move with the same angular velocity, like a rigid turntable.
those in the outer reaches of the disk are slowly spiralling inwards due the presence of dark matter in the galaxy.
those in the disc component move in nearly circular orbits in the plane of the disc and around the galactic centre.
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