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