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