Deck 31: Physics in the 21st Century

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Question
If a photon produces an electron-positron pair and one other particle, the other particle may be a(n):

A) photon.
B) antineutrino.
C) muon.
D) neutrino.
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Question
Which of the following particles is made of two smaller particles?

A) electron
B) proton
C) photon
D) None of these choices.
Question
The Dirac theory predicted that a positron would be:

A) a particle with same mass as an electron but with opposite charge.
B) a particle with negative mass.
C) a negative electron in a negative energy state.
D) All of the above.
Question
Baryons are composed of 3 quarks. If all 3-quark compositions of particles could happen, what would be the highest possible charge for such a particle?

A) There is no upper limit, though the charge is usually less than 3 e
B) 2 e
C) 1 e
D) 3 e
Question
According to present theories, there is a neutrino for all the following particles except:

A) the electron.
B) the tau lepton.
C) the muon.
D) the positive Kaon.
Question
A positron and an electron differ in:

A) spin.
B) charge.
C) mass.
D) energy.
Question
What following quantity is conserved in the following reaction: <strong>What following quantity is conserved in the following reaction:   ?</strong> A) charge B) lepton number C) baryon number D) All of the above. <div style=padding-top: 35px> ?

A) charge
B) lepton number
C) baryon number
D) All of the above.
Question
If a K0 meson at rest decays in 0.90 *10 - 10 s, how far will a K0 meson moving at 0.95c travel through a bubble chamber? (c = 3.00 *108 m/s)

A) 2.6 cm
B) 8.2 cm
C) 9.3 cm
D) 13 cm
Question
Which of the following is not a meson?

A) the phi
B) the kaon
C) the pion
D) All of the above are mesons.
Question
Baryons are composed of _______ quarks, and mesons are composed of ________ quarks.

A) two, two
B) two, three
C) three, three
D) three, two
Question
If a muon at rest decays into an electron at rest according to <strong>If a muon at rest decays into an electron at rest according to   , what is the total energy of the neutrinos?</strong> A)   B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time. C)   D)   <div style=padding-top: 35px> , what is the total energy of the neutrinos?

A) <strong>If a muon at rest decays into an electron at rest according to   , what is the total energy of the neutrinos?</strong> A)   B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time. C)   D)   <div style=padding-top: 35px>
B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time.
C) <strong>If a muon at rest decays into an electron at rest according to   , what is the total energy of the neutrinos?</strong> A)   B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time. C)   D)   <div style=padding-top: 35px>
D) <strong>If a muon at rest decays into an electron at rest according to   , what is the total energy of the neutrinos?</strong> A)   B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time. C)   D)   <div style=padding-top: 35px>
Question
A neutron and a proton have the same:

A) charge.
B) half-life.
C) baryon number.
D) mass.
Question
The exchange of mediating photons can produce:

A) neither a repulsive nor an attractive force.
B) either a repulsive or an attractive force.
C) a repulsive force.
D) an attractive force.
Question
A proton and antiproton each with total energy 800 GeV collide head-on. What is the total energy (particles + energy) released?

A) zero
B) 800 GeV
C) 400 GeV
D) 1600 GeV
Question
Which particle in the free state is least stable?

A) electron
B) neutron
C) photon
D) proton
Question
The size and sign of the charge on an electron is the same as that for:

A) an antiproton.
B) a positron.
C) an antineutron.
D) an antineutrino.
Question
Which, if any, is an elementary particle, i.e., not composed of other particles?

A) the <strong>Which, if any, is an elementary particle, i.e., not composed of other particles?</strong> A) the   particle B) the neutron. C) the electron D) All three are not elementary particles. <div style=padding-top: 35px> particle
B) the neutron.
C) the electron
D) All three are not elementary particles.
Question
Which of the following is not conserved?

A) lepton number
B) meson number
C) baryon number
D) energy
Question
"MeV/c2" is a unit for:

A) energy.
B) nuclear force.
C) mass.
D) momentum.
Question
Which of these particles has the least mass?

A) electron neutrino
B) muon
C) electron
D) pion
Question
Theoretical physicists have had the greatest success in combining which force with the weak nuclear force?

A) gravitational force
B) electromagnetic force
C) strong nuclear force
D) the force caused by the exchange of gluons
Question
The microwave background radiation:

A) represents the leftover glow from the Big Bang.
B) had its slight non-uniformity measured by COBE.
C) was discovered by Penzias and Wilson.
D) All of the above.
Question
The constituent quarks of the proton are uud. What are the charges on u and d?

A) <strong>The constituent quarks of the proton are uud. What are the charges on u and d?</strong> A)   B)   C)   D)   <div style=padding-top: 35px>
B) <strong>The constituent quarks of the proton are uud. What are the charges on u and d?</strong> A)   B)   C)   D)   <div style=padding-top: 35px>
C) <strong>The constituent quarks of the proton are uud. What are the charges on u and d?</strong> A)   B)   C)   D)   <div style=padding-top: 35px>
D) <strong>The constituent quarks of the proton are uud. What are the charges on u and d?</strong> A)   B)   C)   D)   <div style=padding-top: 35px>
Question
Of the quarks u, d, c, s, t, and b, which have positive fractional electronic charge?

A) u, d, c
B) d, s, b
C) s, t, b
D) u, c, t
Question
Which of the following particles has not been observed experimentally?

A) antiproton
B) graviton
C) photon
D) Z0 boson
Question
Which of the following forces is the strongest at near distances?

A) gravitational
B) weak nuclear
C) strong nuclear
D) electromagnetic
Question
Processes in which one type of quark is converted into another type of quark involve which force?

A) electromagnetic
B) strong force
C) weak force
D) gravitational
Question
The strong force is mediated by:

A) the gluon.
B) the W- boson.
C) the W+ boson.
D) All of these choices.
Question
Which force can act over distances comparable to the distance between planets?

A) only electrical
B) only gravitational
C) only magnetic
D) All of these choices.
Question
Assuming the Hubble constant is (21 km/s)/(106 ly), what is the recession speed of a galaxy 300 million parsecs away? (1 parsec = 3.26 ly)

A) 4200 km/s
B) 21,000 km/s
C) 640 km/s
D) 7000 km/s
Question
The cosmic background radiation appears compatible with a blackbody source at what temperature?

A) 0.0003 K
B) 3 K
C) 300 K
D) 0.03 K
Question
Of the following mesons, which is its own antiparticle?

A) <strong>Of the following mesons, which is its own antiparticle?</strong> A)   B)   C)   D) none of those given <div style=padding-top: 35px>
B) <strong>Of the following mesons, which is its own antiparticle?</strong> A)   B)   C)   D) none of those given <div style=padding-top: 35px>
C) <strong>Of the following mesons, which is its own antiparticle?</strong> A)   B)   C)   D) none of those given <div style=padding-top: 35px>
D) none of those given
Question
The weak force that acts between an electron and a quark is caused by the exchange of:

A) photons.
B) W+, W-, or Z0 bosons.
C) gravitons.
D) gluons.
Question
The quark structure of the neutron is udd. What is the quark structure of the antineutron?

A) <strong>The quark structure of the neutron is udd. What is the quark structure of the antineutron?</strong> A)   B) ddu C)   D) udd, since the neutron is its own antiparticle <div style=padding-top: 35px>
B) ddu
C) <strong>The quark structure of the neutron is udd. What is the quark structure of the antineutron?</strong> A)   B) ddu C)   D) udd, since the neutron is its own antiparticle <div style=padding-top: 35px>
D) udd, since the neutron is its own antiparticle
Question
The following reaction can occur by the strong interaction: π\pi 0 + n \rightarrow K+ + Σ\Sigma -. If the quark composition of the n is (udd), the π\pi 0 is  <strong>The following reaction can occur by the strong interaction:   \pi <sup>0</sup> + n  \rightarrow  K<sup>+</sup> +  \Sigma <sup>-</sup>. If the quark composition of the n is (udd), the  \pi <sup>0</sup> is   and the composition of the K<sup>+</sup> is   , what is the quark composition of the  \Sigma <sup>-</sup>?</strong> A) uds B) dds C) sss D)   <div style=padding-top: 35px>  and the composition of the K+ is  <strong>The following reaction can occur by the strong interaction:   \pi <sup>0</sup> + n  \rightarrow  K<sup>+</sup> +  \Sigma <sup>-</sup>. If the quark composition of the n is (udd), the  \pi <sup>0</sup> is   and the composition of the K<sup>+</sup> is   , what is the quark composition of the  \Sigma <sup>-</sup>?</strong> A) uds B) dds C) sss D)   <div style=padding-top: 35px>  , what is the quark composition of the Σ\Sigma -?

A) uds
B) dds
C) sss
D)  <strong>The following reaction can occur by the strong interaction:   \pi <sup>0</sup> + n  \rightarrow  K<sup>+</sup> +  \Sigma <sup>-</sup>. If the quark composition of the n is (udd), the  \pi <sup>0</sup> is   and the composition of the K<sup>+</sup> is   , what is the quark composition of the  \Sigma <sup>-</sup>?</strong> A) uds B) dds C) sss D)   <div style=padding-top: 35px>
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Deck 31: Physics in the 21st Century
1
If a photon produces an electron-positron pair and one other particle, the other particle may be a(n):

A) photon.
B) antineutrino.
C) muon.
D) neutrino.
photon.
2
Which of the following particles is made of two smaller particles?

A) electron
B) proton
C) photon
D) None of these choices.
None of these choices.
3
The Dirac theory predicted that a positron would be:

A) a particle with same mass as an electron but with opposite charge.
B) a particle with negative mass.
C) a negative electron in a negative energy state.
D) All of the above.
a particle with same mass as an electron but with opposite charge.
4
Baryons are composed of 3 quarks. If all 3-quark compositions of particles could happen, what would be the highest possible charge for such a particle?

A) There is no upper limit, though the charge is usually less than 3 e
B) 2 e
C) 1 e
D) 3 e
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5
According to present theories, there is a neutrino for all the following particles except:

A) the electron.
B) the tau lepton.
C) the muon.
D) the positive Kaon.
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6
A positron and an electron differ in:

A) spin.
B) charge.
C) mass.
D) energy.
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7
What following quantity is conserved in the following reaction: <strong>What following quantity is conserved in the following reaction:   ?</strong> A) charge B) lepton number C) baryon number D) All of the above. ?

A) charge
B) lepton number
C) baryon number
D) All of the above.
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8
If a K0 meson at rest decays in 0.90 *10 - 10 s, how far will a K0 meson moving at 0.95c travel through a bubble chamber? (c = 3.00 *108 m/s)

A) 2.6 cm
B) 8.2 cm
C) 9.3 cm
D) 13 cm
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9
Which of the following is not a meson?

A) the phi
B) the kaon
C) the pion
D) All of the above are mesons.
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10
Baryons are composed of _______ quarks, and mesons are composed of ________ quarks.

A) two, two
B) two, three
C) three, three
D) three, two
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11
If a muon at rest decays into an electron at rest according to <strong>If a muon at rest decays into an electron at rest according to   , what is the total energy of the neutrinos?</strong> A)   B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time. C)   D)   , what is the total energy of the neutrinos?

A) <strong>If a muon at rest decays into an electron at rest according to   , what is the total energy of the neutrinos?</strong> A)   B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time. C)   D)
B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time.
C) <strong>If a muon at rest decays into an electron at rest according to   , what is the total energy of the neutrinos?</strong> A)   B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time. C)   D)
D) <strong>If a muon at rest decays into an electron at rest according to   , what is the total energy of the neutrinos?</strong> A)   B) There is insufficient information since the neutrinos are different and have unknown masses, so the answer cannot be given at this time. C)   D)
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12
A neutron and a proton have the same:

A) charge.
B) half-life.
C) baryon number.
D) mass.
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13
The exchange of mediating photons can produce:

A) neither a repulsive nor an attractive force.
B) either a repulsive or an attractive force.
C) a repulsive force.
D) an attractive force.
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14
A proton and antiproton each with total energy 800 GeV collide head-on. What is the total energy (particles + energy) released?

A) zero
B) 800 GeV
C) 400 GeV
D) 1600 GeV
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15
Which particle in the free state is least stable?

A) electron
B) neutron
C) photon
D) proton
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16
The size and sign of the charge on an electron is the same as that for:

A) an antiproton.
B) a positron.
C) an antineutron.
D) an antineutrino.
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17
Which, if any, is an elementary particle, i.e., not composed of other particles?

A) the <strong>Which, if any, is an elementary particle, i.e., not composed of other particles?</strong> A) the   particle B) the neutron. C) the electron D) All three are not elementary particles. particle
B) the neutron.
C) the electron
D) All three are not elementary particles.
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18
Which of the following is not conserved?

A) lepton number
B) meson number
C) baryon number
D) energy
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19
"MeV/c2" is a unit for:

A) energy.
B) nuclear force.
C) mass.
D) momentum.
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k this deck
20
Which of these particles has the least mass?

A) electron neutrino
B) muon
C) electron
D) pion
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21
Theoretical physicists have had the greatest success in combining which force with the weak nuclear force?

A) gravitational force
B) electromagnetic force
C) strong nuclear force
D) the force caused by the exchange of gluons
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Unlock Deck
k this deck
22
The microwave background radiation:

A) represents the leftover glow from the Big Bang.
B) had its slight non-uniformity measured by COBE.
C) was discovered by Penzias and Wilson.
D) All of the above.
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k this deck
23
The constituent quarks of the proton are uud. What are the charges on u and d?

A) <strong>The constituent quarks of the proton are uud. What are the charges on u and d?</strong> A)   B)   C)   D)
B) <strong>The constituent quarks of the proton are uud. What are the charges on u and d?</strong> A)   B)   C)   D)
C) <strong>The constituent quarks of the proton are uud. What are the charges on u and d?</strong> A)   B)   C)   D)
D) <strong>The constituent quarks of the proton are uud. What are the charges on u and d?</strong> A)   B)   C)   D)
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24
Of the quarks u, d, c, s, t, and b, which have positive fractional electronic charge?

A) u, d, c
B) d, s, b
C) s, t, b
D) u, c, t
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25
Which of the following particles has not been observed experimentally?

A) antiproton
B) graviton
C) photon
D) Z0 boson
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26
Which of the following forces is the strongest at near distances?

A) gravitational
B) weak nuclear
C) strong nuclear
D) electromagnetic
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27
Processes in which one type of quark is converted into another type of quark involve which force?

A) electromagnetic
B) strong force
C) weak force
D) gravitational
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k this deck
28
The strong force is mediated by:

A) the gluon.
B) the W- boson.
C) the W+ boson.
D) All of these choices.
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29
Which force can act over distances comparable to the distance between planets?

A) only electrical
B) only gravitational
C) only magnetic
D) All of these choices.
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30
Assuming the Hubble constant is (21 km/s)/(106 ly), what is the recession speed of a galaxy 300 million parsecs away? (1 parsec = 3.26 ly)

A) 4200 km/s
B) 21,000 km/s
C) 640 km/s
D) 7000 km/s
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31
The cosmic background radiation appears compatible with a blackbody source at what temperature?

A) 0.0003 K
B) 3 K
C) 300 K
D) 0.03 K
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32
Of the following mesons, which is its own antiparticle?

A) <strong>Of the following mesons, which is its own antiparticle?</strong> A)   B)   C)   D) none of those given
B) <strong>Of the following mesons, which is its own antiparticle?</strong> A)   B)   C)   D) none of those given
C) <strong>Of the following mesons, which is its own antiparticle?</strong> A)   B)   C)   D) none of those given
D) none of those given
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33
The weak force that acts between an electron and a quark is caused by the exchange of:

A) photons.
B) W+, W-, or Z0 bosons.
C) gravitons.
D) gluons.
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34
The quark structure of the neutron is udd. What is the quark structure of the antineutron?

A) <strong>The quark structure of the neutron is udd. What is the quark structure of the antineutron?</strong> A)   B) ddu C)   D) udd, since the neutron is its own antiparticle
B) ddu
C) <strong>The quark structure of the neutron is udd. What is the quark structure of the antineutron?</strong> A)   B) ddu C)   D) udd, since the neutron is its own antiparticle
D) udd, since the neutron is its own antiparticle
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35
The following reaction can occur by the strong interaction: π\pi 0 + n \rightarrow K+ + Σ\Sigma -. If the quark composition of the n is (udd), the π\pi 0 is  <strong>The following reaction can occur by the strong interaction:   \pi <sup>0</sup> + n  \rightarrow  K<sup>+</sup> +  \Sigma <sup>-</sup>. If the quark composition of the n is (udd), the  \pi <sup>0</sup> is   and the composition of the K<sup>+</sup> is   , what is the quark composition of the  \Sigma <sup>-</sup>?</strong> A) uds B) dds C) sss D)    and the composition of the K+ is  <strong>The following reaction can occur by the strong interaction:   \pi <sup>0</sup> + n  \rightarrow  K<sup>+</sup> +  \Sigma <sup>-</sup>. If the quark composition of the n is (udd), the  \pi <sup>0</sup> is   and the composition of the K<sup>+</sup> is   , what is the quark composition of the  \Sigma <sup>-</sup>?</strong> A) uds B) dds C) sss D)    , what is the quark composition of the Σ\Sigma -?

A) uds
B) dds
C) sss
D)  <strong>The following reaction can occur by the strong interaction:   \pi <sup>0</sup> + n  \rightarrow  K<sup>+</sup> +  \Sigma <sup>-</sup>. If the quark composition of the n is (udd), the  \pi <sup>0</sup> is   and the composition of the K<sup>+</sup> is   , what is the quark composition of the  \Sigma <sup>-</sup>?</strong> A) uds B) dds C) sss D)
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