Exploring the Cosmos - Class Test 2 - Particles, Forces & the Big Bang
1. The size of the observable universe is
93 billion light years.
infinite.
13.7 billion light years.
not known.
2. The cosmological principle states that
the universe is expanding.
time is relative to the observer’s frame of reference.
planets move in elliptical orbits.
if viewed on sufficiently large scales, the properties of the Universe are the same for all observers.
3. The sky is dark at night because
dust obscures the light from far away stars.
the light from very distant stars has not had time to reach us.
the universe is expanding.
far away stars don't emit light in the visible spectrum.
4. Light from distant stars is shifted to the red end of the spectrum because…
the galaxy is rotating.
these stars are very old.
it must pass through intervening dust clouds.
the stars are moving away from us.
5. The Cosmic Microwave Background Radiation is
light emitted from the surface of last scattering.
caused by cosmic rays in the upper atmosphere.
light emitted from binary pulsars.
radio interference caused by roosting pigeons.
6. Eudoxus created a system of 27 concentric spheres to carry heavenly bodies in order to explain
the lack of annual parallax in the celestial sphere.
the tides.
the phases of the moon.
retrograde motion.
7. Aristotle believed that
the stars are Suns just like our own.
Jupiter has moons.
the Earth is at the centre of the solar system.
the Sun is at the centre of the solar system.
8. Newton's Theory of Gravity explains
the motion of Cepheid variable stars.
Kepler’s Laws.
the force of magnetism.
sun-spots.
9. Which of the following statements regarding the Grand Unified Theory is correct?
The GUT is a theory that shows physical laws are obeyed everywhere in the universe.
The GUT is a theory that unifies 3 out of the 4 forces of nature.
The GUT can tell us what happened at the moment of birth of the universe.
The GUT is a theory of everything.
10. Which of the following statements is true?
Photons mediate the electromagnetic force.
Photons are Fermions.
Photons can only be created by annihilating electrons with positrons.
Photons and electrons exert an attractive force
11. During the electroweak era, there were
bosons, atoms and anti atoms.
gravitons, electrons and nuclei.
photons, quarks and protons.
positrons, neutrinos and leptons
12. "Cosmic inflation" refers to
the fact that the expansion of the universe seems to be accelerating.
the very early universe undergoing a sudden and massive expansion.
the increase in temperature as we approach, backward in time, the Big Bang.
the increase of the wavelength of light as we look deeper into space.
13. The electron is an example of a
boson.
gluon.
quark.
lepton.
14. Which force is the weakest in nuclei?
Electromagnetism.
The strong force.
The weak nuclear force.
Gravity.
15. What binds protons and neutrons into nuclei?
The strong force.
Surface tension.
The weak nuclear force.
Gravity.
16. Which of the following eras came earliest in the history of the universe?
The era of galaxies.
The electroweak era.
The era of atoms.
The era of nucleosynthesis.
17. Which of the following observations is evidence of the presence of dark matter?
Distant galaxies are moving faster away from us.
Some stars appear to be moving towards us.
Galaxies are spinning faster than expected.
Distant supernovae appear dimmer.
18. Which of the following statements is false?
The antiparticle of an electron is a positron.
The antiparticle of a photon is a phonon.
The mass of a particle is exactly the same as that of its antiparticle.
The antiparticle of a gluon is a gluon.
19. The gravitational lensing effect is
the bending of light rays by a massive object.
why objects behind a strong gravitational field appear closer.
lenses formed when a thin layer of fluid over an aperture sinks under its own weight.
large telescopic lenses being formed using gravity.
20. Which of the following correctly ranks the forces in ascending order of relative strength?
Weak, strong, gravity.
Electromagnetism, weak, strong.
Weak, strong, electromagnetism.
Gravity, weak, electromagnetism.
21. The electron is an example of a
lepton.
boson.
gluon.
quark.
22. When was the microwave background radiation created?
The era of nuclei.
The era of Nucleosynthesis
The era of atoms.
The Grand Unified Theory era.
23. Today we know that the Milky Way has two disk components. Which of the following statements is correct?
The stars of the thin disk have a stronger oscillatory motion than stars in the thick disc.
The stars in the thin disc have an iron to oxygen ratio that suggests they were formed later than the thick disk.
The stars in the thick disc have an iron to oxygen ratio that suggests they were formed later than the thin disk.
The stars of the two disc components move in opposite direction around the galactic centre.
24. An S0 galaxy can evolve into which of the following galaxy types?
Sa
SBb
Sc
Galaxies cannot evolve from one type into another.
25. Which part of our galaxy features strong star formation?
Halo
Spiral arms
Central bulge
Globular clusters
26. Which of the following statements is not correct?
Our Galaxy has two disks.
The halo components move in nearly circular orbit around the centre of the galaxy.
Open clusters are mainly found in the disk.
The central bulge is thicker than the galactic disk.
27. Which of the following characteristics is true for elliptical Galaxies?
Elliptical galaxies mainly feature Population I stars.
Elliptical galaxies often rotate fast.
In elliptical galaxies there is very little active star formation.
Lots of interstellar medium is present in elliptical galaxies.
28. Which of the following galaxy types belongs to the barred spiral galaxies?
E4
Sb
S0
SBa
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