Astronomy 1020 - Practice Questions

Dr. Gudehus



1)
An Ångstrom unit is


(a)
larger than a micron.
(b)
the same as an electron volt.
(c)
smaller than a micron.
(d)
bigger than a millimeter.



2)
The sequence of colors in a spectrum is in the order of


(a)
red, violet, yellow.
(b)
green, blue, orange.
(c)
violet, red, orange.
(d)
red, orange, yellow.



3)
The electromagnetic force is


(a)
stronger than the nuclear force.
(b)
weaker than gravity.
(c)
stronger than the weak force.
(d)
agrees with all of the above statements.



4)
When light passes through a small opening, it undergoes


(a)
refraction.
(b)
interference.
(c)
dispersion.
(d)
diffraction.



5)
In order to produce a bright line spectrum, we need to start with


(a)
a hot gas.
(b)
a hot solid.
(c)
a blackbody.
(d)
a cool gas.



6)
In hydrogen, the series visible to human eyes is the


(a)
Balmer series.
(b)
Paschen series.
(c)
Lyman series.
(d)
World series.



7)
In order to broaden a spectral line, we should


(a)
make the gas hotter and decrease the pressure.
(b)
make the gas hotter and increase the pressure.
(c)
make the gas cooler and decrease the pressure.
(d)
make the gas cooler and increase the pressure.



8)
If a star is approaching us, its lines are


(a)
shifted blueward.
(b)
shifted redward.
(c)
not shifted.
(d)
doubled.



9)
If the temperature of a blackbody is doubled, its radiated power


(a)
is increased twofold.
(b)
is increased fourfold.
(c)
is increased eightfold.
(d)
is increased sixteenfold.



10)
If the temperature of a blackbody is doubled, the wavelength of its peak output


(a)
is doubled.
(b)
is halved.
(c)
is unaffected.
(d)
is quadrupled.



11)
The sun generates its energy in its


(a)
photosphere.
(b)
corona.
(c)
core.
(d)
chromosphere.



12)
The period of the sunspot cycle is


(a)
29 days.
(b)
11 years.
(c)
1 year.
(d)
24 hours.



13)
The corona is hotter than


(a)
the photosphere.
(b)
the chromosphere.
(c)
sunspots.
(d)
all of the above.



14)
Prominences are


(a)
also known as aurorae.
(b)
found above the chromosphere.
(c)
found below the photosphere.
(d)
another name for sunspots.



15)
An historic period of few sunspots and cool weather is known as


(a)
the dark ages.
(b)
the crash of '29.
(c)
the epicycle.
(d)
the Maunder minimum.



16)
The solar wind is a stream of _________ that passes by the planets.


(a)
hot hydrogen
(b)
electrons and protons
(c)
gas from the corona
(d)
all of the above



17)
The sun's rotational rate is


(a)
faster at its equator.
(b)
faster near its poles.
(c)
equal to that of the earth.
(d)
similar to that of a solid body.



18)
The spectral class of the sun is


(a)
O.
(b)
F.
(c)
G.
(d)
M.



19)
The star which is bluest is the star with a color index of


(a)
0.4.
(b)
-0.4.
(c)
0.0.
(d)
2.0.



20)
Distances to nearby stars can be measured by


(a)
radar.
(b)
sonar.
(c)
trigonometric parallax.
(d)
their rotation rate.



21)
A star with a small proper motion would


(a)
have a small tangential velocity and be nearby.
(b)
have a small tangential velocity and be far away.
(c)
have a large tangential velocity and be nearby.
(d)
have a large tangential velocity and be far away.



22)
The absolute magnitude of a star refers to its magnitude at a distance of


(a)
1 parsec.
(b)
10 parsecs.
(c)
100 parsecs.
(d)
1000 parsecs.



23)
The distance modulus of a star is equal to


(a)
m-M.
(b)
M-m.
(c)
m-M+5.
(d)
M-m+5.



24)
Which spectral class is hotter than the sun?


(a)
G.
(b)
M.
(c)
K.
(d)
B.



25)
A star of high luminosity has a


(a)
low temperature and small radius.
(b)
high temperature and small radius.
(c)
low temperature and large radius.
(d)
high temperature and large radius.



26)
The coolest spectral class is


(a)
A.
(b)
B.
(c)
F.
(d)
K.



27)
The Hertzsprung-Russell diagram is a plot of


(a)
temperature against spectral class.
(b)
spectral class against radius.
(c)
luminosity against spectral class.
(d)
radius against luminosity.



28)
Which is the coolest star?


(a)
a red giant.
(b)
a blue supergiant.
(c)
a white dwarf.
(d)
the sun.



29)
Which does not belong?


(a)
spectroscopic binary.
(b)
visual binary.
(c)
optical binary.
(d)
eclipsing binary.



30)
An astrometric binary is a binary


(a)
whose orbit lies in the plane of the sky.
(b)
whose orbit is a parabola.
(c)
whose distance is greater than 10 parsecs.
(d)
in which one of the members is not visible.



31)
In order to derive the masses of the stars in a binary, we need to employ


(a)
the blackbody formula.
(b)
Newton's law of gravity.
(c)
the conservation of angular momentum.
(d)
the H-R diagram.



32)
A binary system is more likely to be a spectroscopic binary if


(a)
the stars are close together.
(b)
the masses are large.
(c)
the orbit is perpendicular to the plane of the sky.
(d)
all of the above.



33)
The masses we derive from spectroscopic binaries are


(a)
true masses.
(b)
underestimates.
(c)
overestimates.
(d)
true masses if spectra of both stars are visible.



34)
A binary system is more likely to be an eclipsing binary if


(a)
the stars are large compared to their separation.
(b)
the separation is small compared to the stars' radii.
(c)
the plane of the orbit is perpendicular to that of the sky.
(d)
all of the above.



35)
The star Algol or b Persei is a famous example of


(a)
a visual binary.
(b)
a spectroscopic binary.
(c)
an eclipsing binary.
(d)
an astrometric binary.



36)
The stars which deviate from the mass-luminosity relation are


(a)
red giants only.
(b)
main sequence stars.
(c)
red giants and white dwarfs.
(d)
all of the above.



37)
Bok globules are


(a)
ionized hydrogen regions.
(b)
large dark nebulae.
(c)
remnants of old stars.
(d)
small dark nebulae.



38)
Interstellar dust makes starlight


(a)
dimmer and bluer.
(b)
dimmer and redder.
(c)
only bluer.
(d)
only redder.



39)
Interstellar absorption lines are


(a)
broad and highly redshifted.
(b)
narrow and highly redshifted.
(c)
broad and of various redshifts and blueshifts.
(d)
narrow and of various redshifts and blueshifts.



40)
What radiates at a wavelength of 21 cm?


(a)
ionized hydrogen.
(b)
neutral hydrogen.
(c)
molecular hydrogen.
(d)
all of the above.



41)
The most massive stars are about


(a)
10 MSun.
(b)
100 MSun.
(c)
1000 MSun.
(d)
10000 MSun.



42)
Helium undergoes fusion into carbon


(a)
while a star is on the main sequence
(b)
while a star is contracting from a molecular cloud.
(c)
while a star is a red giant.
(d)
while a star is a white dwarf.



43)
When a star exhuasts its supply of hydrogen in its core,


(a)
the core contracts and the envelope expands.
(b)
the core expands and the envelope expands.
(c)
the core contracts and the envelope contracts.
(d)
the core expands and the envelope contracts.



44)
A helium flash occurs because


(a)
the helium is initially at a low temperature.
(b)
the helium is initially at a low density.
(c)
the helium is initially degenerate.
(d)
the helium is initially not in the core.



45)
When a star becomes a red giant,


(a)
its temperature increases and its radius increases.
(b)
its temperature decreases and its radius increases.
(c)
its temperature increases and its radius decreases.
(d)
its temperature decreases and its radius decreases.



46)
For a Cepheid variable,


(a)
a longer period means a lower luminosity.
(b)
the periods are typically less than a day.
(c)
the star lies on the main sequence.
(d)
the longer the period, the more luminous the star.



47)
When we plot a star cluster in the H-R diagram,


(a)
we can test stellar models against observations.
(b)
we can estimate the age of a cluster.
(c)
we can assume than the stars are of about the same age and composition.
(d)
all of the above.



48)
Low mass stars on the lower main sequence will


(a)
eventually burn helium into carbon.
(b)
eventually burn helium into hydrogen.
(c)
eventually contract and become white dwarfs.
(d)
eventually become red giants.



49)
A planetary nebula is


(a)
a nebula from which a young star with planets will form.
(b)
a shell of gas ejected from a red giant.
(c)
an accretion disk around a white dwarf.
(d)
a shell of gas which collects around a main sequence star.



50)
A teaspoon of material from a white dwarf would on the average have as much mass as


(a)
a lead brick.
(b)
a person.
(c)
a truck.
(d)
the moon.



51)
If a star accumulates a core of iron,


(a)
it continues producing energy in the form of iron fusion.
(b)
it slowly contracts.
(c)
it collapses and then explodes as a supernova.
(d)
it becomes a nova.



52)
In order to have synchrotron radiation, one must have


(a)
moving neutral particles and a magnetic field.
(b)
moving charged particles and no magnetic field.
(c)
moving neutral particles and no magnetic field.
(d)
moving charged particles and a magnetic field.



53)
When mass is transferred from one star of a binary star system to the other, the mass


(a)
accumulates in an accretion disk.
(b)
passes through the Langrangian point.
(c)
heats up.
(d)
all of the above.



54)
When a star becomes a nova,


(a)
it is usually a young star.
(b)
it is usually a main sequence star.
(c)
it is usually a red giant.
(d)
it is usually a white dwarf.



55)
Neutron stars


(a)
are slightly smaller than the sun.
(b)
are slightly smaller than a white dwarf.
(c)
are slightly smaller than a red giant.
(d)
none of the above are true.



56)
Pulsars can be explained by the


(a)
vibrations of a white dwarf.
(b)
vibrations of a neutron star.
(c)
lighthouse theory.
(d)
Herbig-Haro theory.



57)
The more massive a white dwarf is,


(a)
the slower it vibrates.
(b)
the smaller its radius is.
(c)
the hotter it is.
(d)
all of the above.



58)
Pulsars slow down with time because


(a)
they are running out of nuclear fuel.
(b)
they are becomming less dense.
(c)
they are converting rotational energy into radiation.
(d)
they are evaporating.



59)
The most likely stage before a neutron star is


(a)
the nova stage.
(b)
the T Tauri stage.
(c)
the main sequence stage.
(d)
the supernova stage.



60)
A pulsar glitch is a


(a)
burst of X-rays.
(b)
burst of radio waves.
(c)
sudden change in the pulsar's period.
(d)
sudden change in the pulsar's position.



61)
Light can escape from the vicinity of a black hole if


(a)
it starts from inside the event horizon.
(b)
it starts from outside the event horizon.
(c)
it starts from inside the event horizon and is directed straight away from the black hole.
(d)
it starts from inside the light circle and is directed straight at the black hole.



62)
The expression "black holes have no hair" means


(a)
black holes have not been verified.
(b)
black holes are old.
(c)
black holes are easy to explain.
(d)
black holes are described by their mass, angular momentum, and charge.



63)
Special relativity tells us that a moving clock


(a)
passes time more slowly as seen by a stationary observer.
(b)
passes time more rapidly as seen by a stationary observer.
(c)
passes time more slowly as seen by an observer traveling with the clock.
(d)
passes time at the same rate as seen by a stationary observer.



64)
General relativity


(a)
correctly explains the advance of Mercury's perihelion.
(b)
correctly explains the deflection of starlight by the sun.
(c)
correctly explains the reddening of light in a gravitational field.
(d)
correctly explains all of the above.



65)
The Milky Way galaxy is


(a)
a spiral galaxy.
(b)
an elliptical galaxy.
(c)
an irregular galaxy.
(d)
a peculiar galaxy.



66)
The Magellanic Clouds can best be seen from


(a)
Alaska.
(b)
Secaucus, New Jersey.
(c)
South America.
(d)
Ponca City, Oklahoma.



67)
The method called "star gauging" was conceived by


(a)
Galileo.
(b)
Herschel.
(c)
Hubble.
(d)
Ptolemy.



68)
In order to determine the sun's location in the Galaxy, Shapley used


(a)
the brightnesses of novae.
(b)
the parallaxes of dwarf stars.
(c)
the diameters of ellipticals.
(d)
the brightnesses of RR Lyrae stars and globular cluster diameters.



69)
The Galaxy's dust and gas is found in its


(a)
central bulge.
(b)
halo.
(c)
disk.
(d)
nucleus.



70)
The distance of the sun from the center of the Galaxy is


(a)
10 parsecs.
(b)
8.5 kiloparsecs.
(c)
1 AU.
(d)
8.5 megaparsecs.



71)
Cosmic rays become trapped in the disk because of the Galaxy's


(a)
intense gravity.
(b)
absorbing dust layer.
(c)
magnetic field.
(d)
large number of stars.



72)
The oldest stars in the Galaxy are found in the


(a)
disk.
(b)
halo.
(c)
spiral arms.
(d)
molecular clouds.



73)
The sun is


(a)
a population I star.
(b)
a population II star.
(c)
a Cepheid.
(d)
an RR Lyrae.



74)
Which would not be a good wavelength region to observe the center of the Galaxy in?


(a)
Radio.
(b)
Optical.
(c)
Infrared.
(d)
Gamma ray.



75)
Cepheids are useful for measuring distances to galaxies because their


(a)
light output is constant.
(b)
high luminosity is correlated with their period.
(c)
absolute magnitudes are always greater than that of the sun.
(d)
diameters are easily measured.



76)
Which is not a way to measure the mass of a galaxy?


(a)
Measurement of its rotation curve.
(b)
Double galaxy method.
(c)
Velocity dispersion method.
(d)
Measurement of its lookback time.



77)
Most galaxies are


(a)
ellipticals.
(b)
spirals.
(c)
irregulars.
(d)
peculiar.



78)
The tuning fork diagram of galaxy types was conceived of by


(a)
Harlow Shapley.
(b)
Henrietta Leavitt.
(c)
Edwin Hubble.
(d)
Johannes Kepler.



79)
S0 galaxies fit between


(a)
ellipticals and irregulars.
(b)
spirals and irregulars.
(c)
ellipticals and spirals.
(d)
Sb galaxies and Sc galaxies.



80)
Galactic cannibalism refers to


(a)
the merging of galaxies.
(b)
black holes at the centers of galaxies.
(c)
rapidly rotating galaxies.
(d)
galaxies which have dark matter.



81)
The arms of spiral galaxies appear prominent because


(a)
they contain stars like the sun.
(b)
they contain O and B stars.
(c)
they contain dust.
(d)
they contain gas.



82)
Starburst galaxies are triggered by


(a)
aging.
(b)
cosmic rays.
(c)
collisions of galaxies.
(d)
dwarf stars.



83)
The Milky Way galaxy is a member of


(a)
the Virgo cluster.
(b)
the Coma cluster.
(c)
the Local Group.
(d)
the Andromeda nebula.



84)
The 3C catalogue is a list of


(a)
X-ray sources.
(b)
gamma-ray sources.
(c)
infrared sources.
(d)
radio sources.



85)
Synchrotron radiation is produced by


(a)
charged particles moving in a gravitational field.
(b)
charged particles moving in a magnetic field.
(c)
radioactive atoms.
(d)
neutral atoms moving in an electric field.



86)
Some radio galaxies have huge double lobes. These lobes are probably


(a)
star clusters.
(b)
clouds of high speed charged particles.
(c)
clouds of dust.
(d)
dark matter.



87)
Head-tail radio galaxies are galaxies that are


(a)
motionless.
(b)
moving throught the intergalactic medium.
(c)
radio-silent.
(d)
featureless.



88)
The centers of active galaxies probably contain


(a)
massive neutron stars.
(b)
massive white dwarfs.
(c)
massive black holes.
(d)
massive planets.



89)
Seyfert galaxies


(a)
are objects with a fairly constant light output.
(b)
have cores which are no different than ordinary galaxies.
(c)
have emission lines from high velocity ionized gas.
(d)
are never spirals.



90)
The galaxy M87


(a)
is a spiral galaxy.
(b)
has a broad light distribution in its center.
(c)
shows no sign of being unusual.
(d)
has a sharply peaked light distribution in its center.



91)
The appearance of a quasar is


(a)
like that of an irregular galaxy.
(b)
like that of a star.
(c)
like that of a spiral galaxy.
(d)
like that of a nebula.



92)
Quasars generally have


(a)
low redshifts.
(b)
high redshifts.
(c)
low luminosity.
(d)
constant light output.



93)
The redshift of an object is a measure of


(a)
the shift in wavelength of its spectral features.
(b)
its shift in position on the sky.
(c)
the change in intensity of its red light.
(d)
its red light.



94)
Which does not belong?


(a)
Seyfert galaxy.
(b)
Andromeda galaxy.
(c)
Quasar.
(d)
BL Lacertid.



95)
A gravitational lens would describe


(a)
a distant object imaged by a nearby low mass object.
(b)
a nearby object imaged by a distant low mass object.
(c)
a distant object imaged by a nearby massive object.
(d)
a nearby object imaged by a distant massive object.



96)
Superluminal expansion is explained by


(a)
objects traveling faster than the speed of light.
(b)
objects traveling almost directly toward us at high velocity.
(c)
objects traveling almost directly toward us at low velocity.
(d)
objects traveling at right angles to our line of sight.



97)
The sky is dark at night because


(a)
of dark matter.
(b)
of absorbing dust.
(c)
of the expanding universe and the finite ages of stars.
(d)
the universe is infinite.



98)
The cosmological principle states that the universe is


(a)
inhomogeneous and isotropic.
(b)
homogeneous and isotropic.
(c)
the same at all times.
(d)
always changing.



99)
The expansion of the universe refers to


(a)
the random movement of galaxies in space.
(b)
the expansion of space, carrying the galaxies along with it.
(c)
the exploding centers of galaxies.
(d)
the gravitational repulsion of galaxies.



100)
If the universe is closed, it


(a)
is finite.
(b)
has no edge.
(c)
has a positive curvature.
(d)
All of the above are true.



101)
The big bang refers to


(a)
the end of the universe.
(b)
the explosive beginning of the universe.
(c)
the noise made by exploding black holes.
(d)
a collision of superclusters.



102)
If the universe has the critical density,


(a)
galaxies will expand to infinity while coasting to a halt.
(b)
its curvature is flat or Euclidean.
(c)
it would contain about 90% dark matter.
(d)
All the above are true.



103)
The Hubble constant refers to


(a)
a nonexpanding universe.
(b)
the ratio of velocity to distance for the expanding universe.
(c)
the curvature of the universe.
(d)
a number in the steady state theory.



104)
The inflationary universe refers to


(a)
the present economic situation.
(b)
a theory of stellar winds.
(c)
Olber's paradox.
(d)
a dramatic expansion of the universe when it was 10-35 seconds old.



105)
Most of the helium in the universe was made


(a)
in the first few minutes of the universe.
(b)
in the cores of red giants.
(c)
at the time of recombination, when the universe was about 106 years old.
(d)
inside black holes.



106)
The most likely place for planets to form is


(a)
around old red giants.
(b)
inside "planetary nebulae".
(c)
around young stars.
(d)
in the vacuum of interstellar space.



107)
The Miller experiment was designed to


(a)
determine the age of blue-green algae.
(b)
determine the mutation rate from cosmic rays.
(c)
reproduce the conditions under which life began on Earth.
(d)
create cells.



108)
The physical basis upon which life extracts energy from its surroundings is based on


(a)
the chemistry of silicon.
(b)
the chemistry of carbon.
(c)
the chemistry of lead.
(d)
the chemistry of hydrogen.



109)
The significance of the Murchison meteorite is that it


(a)
is a fossil.
(b)
came from Mars.
(c)
contains DNA.
(d)
contains amino acids.



110)
Proteins consists of


(a)
Strands of DNA.
(b)
Strands of RNA.
(c)
Amino acids linked together.
(d)
Alternating base pairs.



111)
Living organisms evolve toward


(a)
increasing complexity.
(b)
decreasing complexity.
(c)
shorter and shorter strands of DNA.
(d)
Organisms do not evolve.



112)
In order to communicate with extraterrestrial societies,
(a)
we should send a spaceship to a likely star.
(b)
we should send synchrotron emission to a likely star.
(c)
use as long a wavelength as possible.
(d)
use frequencies near the "water hole".



File translated from TEX by TTH, version 2.21.
On 2 Jan 2000, 19:42.