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