Question 1

An electron is an example of

Accepted Answer

A)  a lepton.
B)  a meson.
C)  a baryon.
D)  a gauge boson.
E)  hadrons. A

Question 2

An electron with an energy of 20 GeV (3.20 × 10-9 J)  moving in the +x direction collides head on with a stationary proton. After the collision, the electron travels in the -x direction. What is the momentum of the electron after the collision? Note that this is an ultrarelativistic collision so that the energy of the moving masses can be approximated by the expression E ≈ pc. The mass of a proton is 1.67 × 10-27 kg and that of an electron is 9.11 × 10-31kg.

Accepted Answer

A)  2.5 × 10-19 kg∙m/s
B)  5.0 × 10-19 kg∙m/s
C)  1.1 × 10-17 kg∙m/s
D)  2.2 × 10-17 kg∙m/s
E)  2.7 × 10-22 kg∙m/s

Question 3

The greater the width of a resonance,

Accepted Answer

A)  the greater the rest energy of the resonance.
B)  the greater the lifetime of the resonance.
C)  the lower the rest energy of the resonance.
D)  the shorter the lifetime of the resonance.
E)  None of the above answers are correct.

Question 4

The competition between the electrostatic force between the protons in a nucleus and the strong nuclear force determines whether a nucleus is stable.

Accepted Answer

A) True 
 B)False

Question 5

One of the particle groups listed below includes two other groups on the list. Which group is it?

Accepted Answer

A)  leptons
B)  hadrons
C)  mesons
D)  bosons.
E)  baryons

Question 6

One reason a photon could not create an odd number of electrons and positrons is that such a process would

Accepted Answer

A)  not conserve charge.
B)  not conserve energy.
C)  require photon energies that are not attainable.
D)  result in the creation of mass.
E)  result in the destruction of mass.

Question 7

When a positronium atom (electron + positron)  decays, it emits two photons. What are the energies of the photons?

Accepted Answer

A)  0.511 MeV and 1.022 MeV
B)  0.225 MeV and 1.022 MeV
C)  0.225 MeV and 0.285 MeV
D)  0.256 MeV and 0.256 MeV
E)  0.511 MeV and 0.511 MeV

Question 8

Particles that do not interact via the strong force but do interact via the weak nuclear force (and presumably by the much weaker gravitation force)  are called

Accepted Answer

A)  gauge bosons.
B)  leptons.
C)  baryons.
D)  mesons.
E)  hadrons.

Question 9

Is the following decay allowed? Σ+ → p + π+

Accepted Answer

A)  Yes.
B)  No, because charge is not conserved.
C)  No, because mass is created.
D)  No, because lepton number is not conserved.

Question 10

The proton composition by quarks is

Accepted Answer

A)  u  d.
B)  uud.
C)  udd.
D)  u  .
E)  u  d. B

Question 11

Is the following decay permissible? Σ+ → Λ° + π+

Accepted Answer

A)  Yes.
B)  No, because charge is not conserved.
C)  No, because mass is created.
D)  No, because lepton number is not conserved.

Question 12

The neutrino has

Accepted Answer

A)  enormous rest mass, positive charge, and spin quantum number 1/2.
B)  enormous rest mass, no charge, and spin quantum number 1.
C)  negligible rest mass, negative charge, and spin quantum number 1.
D)  negligible rest mass, no charge, and spin quantum number 1/2.
E)  none of the given answers

Question 13

The Large Hadron Collider is expected to produce protons with kinetic energy 7 TeV. What is the speed of these protons?

Accepted Answer

A)  less than 0.9000 c
B)  0.9500 c
C)  0.9990 c
D)  greater than 0.9999 c
E)  0.9000 c

Question 14

An electron undergoes a collision with a proton. In the center of mass system, the energy of the electron is 4000 MeV. What is the energy of the electron in the lab system, where the proton is at rest before the collision?

Accepted Answer

A)  34 GeV
B)  37 GeV
C)  40 GeV
D)  43 GeV
E)  46 GeVF) 52 GeV

Question 15

A neutron is an example of

Accepted Answer

A)  a lepton.
B)  a meson.
C)  a baryon.
D)  a gauge boson.
E)  none of the above.

Question 16

If electrons are accelerated from rest in a 30 MeV tandem Van de Graaff Accelerator, what is their final kinetic energy?

Accepted Answer

A)  15 MeV
B)  20 MeV
C)  30 MeV
D)  40 MeV
E)  60 MeV

Question 17

A deuteron has the same charge as a proton but approximately twice the proton mass. Suppose deuterons are being accelerated in a cyclotron in an orbit of radius 75 cm at a frequency of 8.0 MHz. What magnetic field is needed?

Accepted Answer

A)  0.011 T
B)  0.11 T
C)  1.1 T
D)  11 T
E)  111 T C

Question 18

A photon is an example of

Accepted Answer

A)  a lepton.
B)  a meson.
C)  a baryon.
D)  a gauge boson.
E)  hadrons.

Question 19

A proton is an example of

Accepted Answer

A)  a lepton.
B)  a meson.
C)  a baryon.
D)  a gauge boson.
E)  none of the above.

Question 20

The reaction p + e- → - →   + e+ is not possible because A) the baryon number is not conserved. B) the lepton number is not conserved. C) the angular momentum cannot conserved. D) the charge is not conserved. E) The statement is untrue; the reaction is possible." class="answers-bank-image d-inline" rel="preload" > + e+ is not possible because

Accepted Answer

A)  the baryon number is not conserved.
B)  the lepton number is not conserved.
C)  the angular momentum cannot conserved.
D)  the charge is not conserved.
E)  The statement is untrue; the reaction is possible.

Exam 43: Elementary Particle

An electron is an example of

Correct Answer
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A

Correct Answer
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The greater the width of a resonance,

Correct Answer
verified

The competition between the electrostatic force between the protons in a nucleus and the strong nuclear force determines whether a nucleus is stable.

Correct Answer
verified

One of the particle groups listed below includes two other groups on the list. Which group is it?

Correct Answer
verified

One reason a photon could not create an odd number of electrons and positrons is that such a process would

Correct Answer
verified

When a positronium atom (electron + positron) decays, it emits two photons. What are the energies of the photons?

Correct Answer
verified

Particles that do not interact via the strong force but do interact via the weak nuclear force (and presumably by the much weaker gravitation force) are called

Correct Answer
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Is the following decay allowed? Σ⁺ → p + π⁺

Correct Answer
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The proton composition by quarks is

Correct Answer
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B

Is the following decay permissible? Σ⁺ → Λ° + π⁺

Correct Answer
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The neutrino has

Correct Answer
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The Large Hadron Collider is expected to produce protons with kinetic energy 7 TeV. What is the speed of these protons?

Correct Answer
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An electron undergoes a collision with a proton. In the center of mass system, the energy of the electron is 4000 MeV. What is the energy of the electron in the lab system, where the proton is at rest before the collision?

Correct Answer
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A neutron is an example of

Correct Answer
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If electrons are accelerated from rest in a 30 MeV tandem Van de Graaff Accelerator, what is their final kinetic energy?

Correct Answer
verified

A deuteron has the same charge as a proton but approximately twice the proton mass. Suppose deuterons are being accelerated in a cyclotron in an orbit of radius 75 cm at a frequency of 8.0 MHz. What magnetic field is needed?

Correct Answer
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C

A photon is an example of

Correct Answer
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A proton is an example of

Correct Answer
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The reaction p + e^- → + e⁺is not possible because

Correct Answer
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Exam 43: Elementary Particle

An electron is an example of

Correct AnswerverifiedA

Correct AnswerverifiedShow Answer

The greater the width of a resonance,

Correct AnswerverifiedShow Answer

The competition between the electrostatic force between the protons in a nucleus and the strong nuclear force determines whether a nucleus is stable.

Correct AnswerverifiedShow Answer

One of the particle groups listed below includes two other groups on the list. Which group is it?

Correct AnswerverifiedShow Answer

One reason a photon could not create an odd number of electrons and positrons is that such a process would

Correct AnswerverifiedShow Answer

When a positronium atom (electron + positron) decays, it emits two photons. What are the energies of the photons?

Correct AnswerverifiedShow Answer

Particles that do not interact via the strong force but do interact via the weak nuclear force (and presumably by the much weaker gravitation force) are called

Correct AnswerverifiedShow Answer

Is the following decay allowed? Σ+ → p + π+

Correct AnswerverifiedShow Answer

The proton composition by quarks is

Correct AnswerverifiedB

Is the following decay permissible? Σ+ → Λ° + π+

Correct AnswerverifiedShow Answer

The neutrino has

Correct AnswerverifiedShow Answer

The Large Hadron Collider is expected to produce protons with kinetic energy 7 TeV. What is the speed of these protons?

Correct AnswerverifiedShow Answer

An electron undergoes a collision with a proton. In the center of mass system, the energy of the electron is 4000 MeV. What is the energy of the electron in the lab system, where the proton is at rest before the collision?

Correct AnswerverifiedShow Answer

A neutron is an example of

Correct AnswerverifiedShow Answer

If electrons are accelerated from rest in a 30 MeV tandem Van de Graaff Accelerator, what is their final kinetic energy?

Correct AnswerverifiedShow Answer

A deuteron has the same charge as a proton but approximately twice the proton mass. Suppose deuterons are being accelerated in a cyclotron in an orbit of radius 75 cm at a frequency of 8.0 MHz. What magnetic field is needed?

Correct AnswerverifiedC

A photon is an example of

Correct AnswerverifiedShow Answer

A proton is an example of

Correct AnswerverifiedShow Answer

The reaction p + e- → + e+ is not possible because

Correct AnswerverifiedShow Answer

Correct Answer
verified
A

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Is the following decay allowed? Σ⁺ → p + π⁺

Correct Answer
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Correct Answer
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B

Is the following decay permissible? Σ⁺ → Λ° + π⁺

Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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C

Correct Answer
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Correct Answer
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The reaction p + e^- → + e⁺is not possible because

Correct Answer
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