Exploring the Cosmos - Class Test 1 - Complete A
1. Which of the following parameters is the same for all electromagnetic waves propagating in a vacuum?
Colour
Speed
Wavelength
Amplitude
2. Which of the following statements correctly describes the wavelength of an electromagnetic wave?
The wavelength is the distance between two consecutive peaks.
The wavelength is the distance travelled by the wave in a short time.
The wavelength is the distance between a trough and a peak.
The wavelength is the distance travelled by the wave in 1 second.
3. Diffraction gratings are used to
reduce diffraction of telescopes.
increase the resolution of telescopes.
detect infrared radiation.
break up light into a spectrum.
4. The objective of a telescope is
the object under observation.
the adaptor between the telescope and the human eye.
the reason why that telescope has been built.
the part of it which first converges the light.
5. The speed of light in glass is
increased by approximately 50%
reduced by approximately 60%
the same as in vacuum
reduced by approximately 1%
6. An electromagnetic wave having a wavelength of 550 nm is:
visible radiation.
infrared radiation.
gamma radiation.
ultra-violet radiation.
7. Roughly how many stars are there in our own galaxy?
100 million
1 million
1 billion
100 billion
8. Which of the following statements is true?
The parallax of an object increases as the distance from observer to object increases.
The parallax of an object decreases as the distance from observer to object decreases.
The parallax of an object does not depend on the distance between observer and object.
The parallax of an object decreases as the distance from observer to object increases.
9. Which star has the greatest observed proper motion?
Betelgeuse
Barnard
Epsilon Eridani
Proxima Centauri
10. How much bigger, approximately, is the mass of the Sun in comparison to the mass of the Earth?
3,300 times bigger
330,000 times bigger
330 times bigger
33,000 times bigger
11. Which of the following regions of our Sun is the hottest?
Convection zone
Chromosphere
Photosphere
Corona
12. Who developed the first systematic method for naming stars in 1603?
John Flamsteed
Johann Bayer
Henry Draper
Joseph de Lalande
13. The amount of solar energy reaching the surface of the Earth
1,400,000 Wm^-2
1,400 Wm^-2
14,000 Wm^-2
140,000 Wm^-2
14. The presence of which element in stars provides direct evidence that heavy elements really do form in the cores of stars?
Pluotnium-242
Technitium-99
Thorium-232
Bismuth-209
15. Which element is the second most abundant in our universe?
Helium
Iron
Silicon
Hydrogen
16. How does a star of spectral type A0 compare to one of spectral type A5?
It is slightly smaller.
It is slightly cooler.
It is slightly bigger.
It is slightly hotter.
17. The colour index of a star is indicative of its
temperature.
diameter.
luminosity.
distance.
18. What is the approximate temperature of the photosphere of our Sun?
10,000 K
5,800 K
2 million K
15 million K
19. The sky is dark at night because
our eyes are not sensitive enough.
the universe is only sparsely populated with stars.
some stars are so far away that their light has not yet reached us.
there is dark matter in between the stars.
20. What is the observable universe?
The portion of the universe that our eyes can see.
Part of the universe that the most powerful telescopes can resolve.
All parts of the universe that are not obscured by celestial objects.
The portion of the universe from which light had enough time to travel to us.
21. We know distant galaxies are receding because
the wavelength of light from these galaxies gets longer.
these galaxies appear smaller and smaller.
the light from these galaxies gets dimmer over time.
modern telescopes allow us to measure distance accurately.
22. Far away stars and galaxies are older. Is this true or false, and why?
True, because distance and time are interchangeable variables in cosmology.
False, the age of stars and galaxies does not depend on their distance from us.
True, because light from these takes longer to reach us.
False, because the universe started at the same time.
23. A closed universe
has negative curvature, like a saddle.
is flat, like a plane.
will expand forever.
has positive curvature, like a sphere.
24. If galaxy A is four times more distant than galaxy B, then according to the Hubble Law, galaxy A will recede ___________ than galaxy B.
16 times faster
0.25 times faster
4 times faster
2 times faster
25. Population I stars in our galaxy are
typically found in regions with little new star formation and are "metal" rich.
typically found in regions with new star formation and are "metal" rich.
typically found in regions with little new star formation and are "metal" poor.
typically found in regions with new star formation and are "metal" poor.
26. The density wave theory is a mechanism used to explain
the formation of new stars in the arms of a spiral galaxies.
the behaviour of Cepheid variables.
the very large scale structures seen in the Universe such as the Great Wall.
the merger of elliptical galaxies.
27. Neutral hydrogen can be detected by astronomers because
it reflects blue light from nearby stars.
it forms dark clouds in the disc of a spiral galaxy.
it radiates a sharp 21 cm radio signal.
it glows with a bright blue colour.
28. Of the stars in our galaxy
those in the spherical component move in circular orbits that have random orientations.
those in the disc component move in circular orbits that have random orientations.
those in the spherical component move in elliptical orbits that have a random orientation.
those in the nucleus orbit the centre in the opposite direction to those in the disc component.
29. Our Sun and solar system are
stationary in our Galaxy.
rotating about the centre of the Galaxy once every million years.
moving directly towards a supermassive black hole at the centre of the Galaxy and will merge into the centre in 240 million years.
rotating around the centre of the Galaxy once every 240 million years.
30. In our galaxy, dense concentrations gas and dust are found
everywhere in the disc.
everywhere in the galaxy.
in the thin disc.
in the central bulge.
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