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