Complete Test Bank Quarks, Leptons, and the Big Bang Ch.44

Chapter: Chapter 44

Learning Objectives

LO 44.1.0 Solve problems related to general properties of elementary particles.

LO 44.1.1 Identify that a great many elementary particles exist or can be created and that nearly all of them are unstable.

LO 44.1.2 For the decay of an unstable particle, apply the same decay equations as used for the radioactive decay of nuclei.

LO 44.1.3 Identify spin as the intrinsic angular momentum of a particle.

LO 44.1.4 Distinguish fermions from bosons, and identify which are required to obey the Pauli exclusion principle.

LO 44.1.5 Distinguish leptons and hadrons, and then identify the two types of hadrons.

LO 44.1.6 Distinguish particle from antiparticle, and identify that if they meet, they undergo annihilation and are transformed into photons or into other elementary particles.

LO 44.1.7 Distinguish the strong force and the weak force.

LO 44.1.8 To see if a given process for elementary particles is physically possible, apply the conservation laws for charge, linear momentum, spin angular momentum, and energy (including mass energy).

LO 44.2.0 Solve problems related to leptons, hadrons, and strangeness.

LO 44.2.1 Identify that there are six leptons (with an antiparticle each) in three families, with a different type of neutrino in each family.

LO 44.2.2 To see if a given process for elementary particles if physically possible, determine whether it conservers lepton number and whether it conserves the individual family lepton numbers.

LO 44.2.3 Identify that there is a quantum number called baryon number associated with the baryons.

LO 44.2.4 To see if a given process for elementary particles if physically possible, determine whether the process conserves baryon number.

LO 44.2.5 Identify that there is a quantum number called strangeness associated with some of the baryons and mesons.

LO 44.2.6 Identify that the strangeness must be conserved in an interaction involving the strong force, but this conservation law can be broken for other interactions.

LO 44.2.7 Describe the eightfold-way patterns.

LO 44.3.0 Solve problems related to quarks and messenger particles.

LO 44.3.1 Identify that there are six quarks (with an antiparticle for each).

LO 44.3.2 Identify that baryons contain three quarks (or antiquarks) and mesons contain an quark and an antiquark, and that many of these hadrons are excited states of the basic quark combinations.

LO 44.3.3 For a given hadron, identify the quark it contains, and vice-versa.

LO 44.3.4 Identify virtual particles.

LO 44.3.5 Apply the relationship between the violation of energy by a virtual particle and the time interval allowed for that violation (an uncertainty principle written in terms of energy).

LO 44.3.6 Identify the messenger particles for electromagnetic interactions, weak interactions, and strong interactions.

LO 44.4.0 Solve problems related to cosmology.

LO 44.4.1 Identify that the universe (all of spacetime) began with the big bang and has been expanding ever since.

LO 44.4.2 Identify that all distant galaxies (and thus their stars, black holes, etc.), in all directions, are receding from us because of the expansion.

LO 44.4.3 Apply Hubble's law to relate the recession speed v of a distant galaxy, its distance r from us, and the Hubble constant H.

LO 44.4.4 Apply the Doppler equation for the red shift of light to relate the wavelength shift Δλ, the recession speed v, and the proper wavelength λ₀ of the emission.

LO 44.4.5 Approximate the age of the universe using the Hubble constant.

LO 44.4.6 Identify the cosmic background radiation and explain the importance of its detection.

LO 44.4.7 Explain the evidence for the dark matter that apparently surrounds every galaxy.

LO 44.4.8 Discuss the various stages of the universe from very soon after the big bang until atoms began to form.

LO 44.4.9 Identify that the expansion of the universe is being accelerated by some unknown property dubbed dark energy.

LO 44.4.10 Identify that the total energy of baryonic matter (protons and neutrons) is only a small part of the total energy of the universe.

Multiple Choice

1. Which of the following particles is stable?

A) Neutron

B) Proton

C) Pion

D) Muon

E) Kaon

Difficulty: E

Section: 44-1

Learning Objective 44.1.1

2. A particle can decay to particles with greater rest mass:

A) only if antiparticles are produced

B) only if photons are also produced

C) only if neutrinos are also produced

D) only if the original particle has kinetic energy

E) never

Difficulty: E

Section: 44-1

Learning Objective 44.1.2

3. A particle with spin angular momentum is called a:

A) lepton

B) hadron

C) fermion

D) boson

E) electron

Difficulty: E

Section: 44-1

Learning Objective 44.1.4

4. A particle with spin angular momentum is called a:

A) lepton

B) hadron

C) fermion

D) boson

E) electron

Difficulty: E

Section: 44-1

Learning Objective 44.1.4

5. An example of a fermion is a:

A) photon

B) pion

C) neutrino

D) kaon

E) none of these

Difficulty: E

Section: 44-1

Learning Objective 44.1.4

6. An example of a boson is a:

A) photon

B) electron

C) neutrino

D) proton

E) neutron

Difficulty: E

Section: 44-1

Learning Objective 44.1.4

7. All particles with spin angular momentum :

A) interact via the strong force

B) travel at the speed of light

C) obey the Pauli exclusion principle

D) have non-zero rest mass

E) are charged

Difficulty: E

Section: 44-1

Learning Objective 44.1.4

8. Which of the following statements is correct?

A) All leptons are bosons.

B) All hadrons are fermions.

C) The two types of mesons are leptons and baryons.

D) The two types of hadrons are mesons and baryons.

E) The two types of leptons are mesons and fermions.

Difficulty: E

Section: 44-1

Learning Objective 44.1.5

9. Two particles interact to produce only photons, with the original particles disappearing. The particles must have been:

A) mesons

B) strange particles

C) strongly interacting

D) leptons

E) a particle-antiparticle pair

Difficulty: M

Section: 44-1

Learning Objective 44.1.6

10. All leptons interact with each other via the:

A) strong force

B) weak force

C) electromagnetic force

D) strange force

E) none of these

Difficulty: E

Section: 44-1

Learning Objective 44.1.7

11. An electron participates in:

A) the electromagnetic and weak forces only

B) the strong and weak forces only

C) the electromagnetic and gravitational forces only

D) the electromagnetic, gravitational, and weak forces only

E) the electromagnetic, gravitational, and strong forces only

Difficulty: E

Section: 44-1

Learning Objective 44.1.7

12. A proton cannot decay into a neutron, a positron, and an electron neutrino. Which of the following conservation laws would be violated if it did?

A) Charge

B) Linear momentum

C) Angular momentum

D) Energy

E) None of the above

Difficulty: M

Section: 44-1

Learning Objective 44.1.8

13. A neutral lepton cannot decay into two neutrinos. Of the following conservation laws, which would be violated if it did?

A) Energy

B) Baryon number

C) Linear Momentum

D) Angular momentum

E) None of the above

Difficulty: M

Section: 44-2

Learning Objective 44.2.0

14. The interaction ^– + p  K^– + ⁺ violates the principle of conservation of:

A) baryon number

B) lepton number

C) strangeness

D) angular momentum

E) none of these

Difficulty: M

Section: 44-2

Learning Objective 44.2.0

15. Different types of neutrinos can be distinguished from each other by:

A) the directions of their spins

B) the leptons with which they interact

C) the baryons with which they interact

D) the number of photons that accompany them

E) their baryon numbers

Difficulty: E

Section: 44-2

Learning Objective 44.2.1

16. Which of the following particles has a lepton number of zero?

A) e⁺

B) ⁺

C) v_e

D)

E) p

Difficulty: E

Section: 44-2

Learning Objective 44.2.2

17. Which of the following particles has a lepton number of +1?

A) e⁺

B) ⁺

C) ^–

D)

E) p

Difficulty: E

Section: 44-2

Learning Objective 44.2.2

18. ⁺ represents a pion (a meson), ^– represents a muon (a lepton), v_e represents an electron neutrino (a lepton), and v_ represents a muon neutrino (a lepton). Which of the following decays might occur?

A) ⁺  ^– + v_

B) ⁺  ⁺ + v_e

C)

D)

E) ⁺  ⁺ + v_

Difficulty: M

Section: 44-2

Learning Objective 44.2.2

19. A neutron cannot decay into a neutrino and an antineutrino. This decay would violate baryon number conservation and which other conservation law?

A) Energy

B) Lepton number

C) Electric charge

D) Linear momentum

E) Angular momentum

Difficulty: M

Section: 44-2

Learning Objective 44.2.2

20. The stability of the proton is predicted by the laws of conservation of energy and conservation of:

A) momentum

B) angular momentum

C) baryon number

D) lepton number

E) strangeness

Difficulty: E

Section: 44-2

Learning Objective 44.2.4

21. Two baryons interact to produce pions only, the original baryons disappearing. One of the baryons must have been:

A) a proton

B) an omega minus

C) a sigma

D) an antiparticle

E) none of these

Difficulty: M

Section: 44-2

Learning Objective 44.2.4

22. When a kaon decays via the strong interaction the products must include a:

A) baryon

B) lepton

C) strange particle

D) electron

E) neutrino

Difficulty: E

Section: 44-2

Learning Objective 44.2.6

23. Strangeness is conserved in:

A) all particle decays

B) no particle decays

C) all weak particle decays

D) all strong particle decays

E) some strong particle decays

Difficulty: E

Section: 44-2

Learning Objective 44.2.6

24. The interaction ^– + p  ^– + ⁺ violates the principle of conservation of:

A) baryon number

B) lepton number

C) strangeness

D) angular momentum

E) none of these

Difficulty: M

Section: 44-2

Learning Objective 44.2.6

25. A baryon with strangeness –1 decays via the strong interaction into two particles, one of which is a baryon with strangeness 0. The other is:

A) a baryon with strangeness 0

B) a baryon with strangeness +1

C) a meson with strangeness –1

D) a meson with strangeness +1

E) a meson with strangeness 0

Difficulty: M

Section: 44-2

Learning Objective 44.2.6

26. A baryon with strangeness 0 decays via the strong interaction into two particles, one of which is a baryon with strangeness +1. The other is:

A) a baryon with strangeness 0

B) a baryon with strangeness +1

C) a baryon with strangeness –1

D) a meson with strangeness +1

E) a meson with strangeness –1

Difficulty: M

Section: 44-2

Learning Objective 44.2.6

27. All known quarks and antiquarks have:

A) charges that are multiples of e and integer baryon numbers

B) charges that are multiples of e and baryon numbers that are either +1/3 or –1/3

C) charges that are multiples of e/3 and integer baryon numbers

D) charges that are multiples of e/3 and baryon numbers that are either +1/3 or –1/3

E) charges that are multiples of 2e/3 and baryon numbers that are either +1/3 or –1/3

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

28. The baryon number of a quark is:

A) 0

B) –1/3

C) 1/3

D) 2/3

E) 1

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

29. In order of increasing strength the four basic interactions are:

A) gravitational, weak, electromagnetic, and strong

B) gravitational, electromagnetic, weak, and strong

C) weak, gravitational, electromagnetic, and strong

D) weak, electromagnetic, gravitational, and strong

E) strong, electromagnetic, weak, and gravitational

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

30. The two basic interactions that have finite ranges are:

A) electromagnetic and gravitational

B) electromagnetic and strong

C) electromagnetic and weak

D) gravitational and weak

E) weak and strong

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

31. A certain process produces baryons that decay with a lifetime of 4  10^–24 s. The decay is a result of:

A) the gravitational interaction

B) the weak interaction

C) the electromagnetic interaction

D) the strong interaction

E) some combination of the above

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

32. A certain process produces mesons that decay with a lifetime of 6  10^–10 s. The decay is a result of:

A) the gravitational interaction

B) the weak interaction

C) the electromagnetic interaction

D) the strong interaction

E) some combination of the above

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

33. Compared to the lifetimes of particles that decay via the weak interaction, the lifetimes of particles that decay via the strong interaction are:

A) 10^–23 times as long

B) 10^–12 times as long

C) 10¹² times as long

D) 10²⁴ times as long

E) about the same

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

34. A down quark can be changed into an up quark (plus other particles perhaps) by:

A) the gravitational interaction

B) the weak interaction

C) the electromagnetic interaction

D) the strong interaction

E) none of these

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

35. The color theory explains why quarks:

A) form particles in pairs and triplets

B) have charge that is a multiple of e/3

C) have spin

D) have mass

E) none of the above

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

36. Color is carried by:

A) only quarks

B) only leptons

C) only quarks and leptons

D) only quarks and gluons

E) only photons and gluons

Difficulty: E

Section: 44-3

Learning Objective 44.3.0

37. How many different flavors of quarks are there (not counting antiquarks)?

A) 1

B) 3

C) 6

D) 12

E) 18

Difficulty: E

Section: 44-3

Learning Objective 44.3.1

38. Quarks are the constituents of:

A) all particles

B) all leptons

C) all strongly interacting particles

D) only strange particles

E) only mesons

Difficulty: E

Section: 44-3

Learning Objective 44.3.2

39. Any meson is a combination of:

A) three quarks

B) two quarks and an antiquark

C) one quark and two antiquarks

D) one quark and one antiquark

E) two quarks

Difficulty: E

Section: 44-3

Learning Objective 44.3.2

40. A baryon is a combination of:

A) three quarks

B) two quarks and an antiquark

C) one quark and two antiquarks

D) one quark and one antiquark

E) two quarks

Difficulty: E

Section: 44-3

Learning Objective 44.3.2

41. The up quark u has charge +2e/3 and strangeness 0; the down quark d has charge –e/3 and strangeness 0; the strange quark s has charge –e/3 and strangeness –1. This means there can be no baryon with:

A) charge 0 and strangeness 0

B) charge –e and strangeness –1

C) charge +e and strangeness –1

D) charge +e and strangeness –2

E) charge 0 and strangeness –2

Difficulty: M

Section: 44-3

Learning Objective 44.3.2

42. The up quark u has charge +2/3 and strangeness 0; the down quark d has charge –1/3 and strangeness 0; the strange quark s has charge –1/3 and strangeness –1. This means there can be no meson with:

A) charge 0 and strangeness –1

B) charge –1 and strangeness –1

C) charge +1 and strangeness –1

D) charge –1 and strangeness +1

E) charge 0 and strangeness +1

Difficulty: M

Section: 44-3

Learning Objective 44.3.2

43. The quark content of a proton is:

A) uuu

B) uud

C) udd

D) ddd

E) uds

Difficulty: E

Section: 44-3

Learning Objective 44.3.3

44. The quark content of a ⁺ meson is:

A) uu

B)

C)

D)

E)

Difficulty: E

Section: 44-3

Learning Objective 44.3.3

45. In terms of quark content a beta decay can be written:

A) udd  uud + e^– +

B) udd  udd + dd + 

C) udd  udd + dd + e^–

D) udd  uud + ud + 

E) udd  uud + e⁺ +

Difficulty: M

Section: 44-3

Learning Objective 44.3.3

46. The mass of the W boson is 80 GeV/c². During beta decay, a virtual W is created. In order not to visibly violate conservation of energy, what is the longest time the W particle can be in existence?

A) 0 s

B) 8 x 10^-45 s

C) 8 x 10^-36 s

D) 8 x 10^-27 s

E) There is no limit on the time the W can exist.

Difficulty: M

Section: 44-3

Learning Objective 44.3.5

47. Messenger particles of the electromagnetic interaction are called:

A) gluons

B) photons

C) W and Z

D) gravitons

E) pions

Difficulty: E

Section: 44-3

Learning Objective 44.3.6

48. Messenger particles of the strong interaction are called:

A) gluons

B) photons

C) W and Z

D) gravitons

E) Higgs

Difficulty: E

Section: 44-3

Learning Objective 44.3.6

49. Messenger particles of the weak interaction are called:

A) gluons

B) photons

C) W and Z

D) gravitons

E) pions

Difficulty: E

Section: 44-3

Learning Objective 44.3.6

50. If dark matter did not exist it is likely that:

A) the universe would expand forever

B) the universe would begin contracting soon

C) the night sky would be brighter

D) the night sky would be darker

E) we would be able to see the center of the universe

Difficulty: E

Section: 44-4

Learning Objective 44.4.0

51. Hubble's law is evidence that:

A) the speed of light is increasing

B) the universe is expanding

C) the Earth is slowing down in its orbit

D) galaxies have rotational motion

E) none of the above

Difficulty: E

Section: 44-4

Learning Objective 44.4.3

52. Objects in the universe are receding from us with a speed that is proportional to:

A) the reciprocal of the square of their distance from us

B) the reciprocal of their distance from us

C) their distance from us

D) the square of their distance from us

E) their distance from the center of the universe

Difficulty: E

Section: 44-4

Learning Objective 44.4.3

53. A galaxy 200 Mpc from us has a recessional velocity of about 14,000 km/s. If it emits radiation at a wavelength of 121 nm, how much is that wavelength shifted when we observe it?

A) 5.7 x 10^-12 m

B) 5.7 x 10^-10 m

C) 5.7 x 10^-9 m

D) 5.7 x 10^-7 m

E) 5.7 x 10^-6 m

Difficulty: E

Section: 44-4

Learning Objective 44.4.4

54. The velocities of distant objects in the universe indicate that the time elapsed since the big bang is about:

A) 10⁵ y

B) 10¹⁰ y

C) 10¹⁵ y

D) 10²⁰ y

E) 10²⁵ y

Difficulty: E

Section: 44-4

Learning Objective 44.4.5

55. The intensity of the microwave background radiation, a remnant of the big bang:

A) is greatest in directions toward the center of the galaxy

B) is least in directions toward the center of the galaxy

C) is proportional to the reciprocal of the distance from us

D) is proportional to the square of the distance from us

E) is nearly the same in all directions

Difficulty: E

Section: 44-4

Learning Objective 44.4.6

56. The microwave background radiation is a result of the big bang. The big bang also resulted in a uniform distribution of background:

A) electrons

B) quarks

C) gluons

D) neutrinos

E) atoms

Difficulty: E

Section: 44-4

Learning Objective 44.4.6

57. Dark matter is suspected to exist in the universe because:

A) the night sky is dark between stars

B) the orbital period of stars in the outer parts of a galaxy is greater than the orbital period of stars near the galactic center

C) the orbital period of stars in the outer parts of a galaxy is less than the orbital period of stars near the galactic center

D) the orbital period of stars in the outer parts of a galaxy is about the same as the orbital period of stars near the galactic center

E) all galaxies have about the same mass

Difficulty: E

Section: 44-4

Learning Objective 44.4.7

58. What discovery in 1998 changed our understanding of the overall history of the universe?

A) The universe is permeated with radiation at microwave frequencies.

B) The universe is expanding, and has been since the Big Bang.

C) The expansion of the universe is slowing, and will eventually reverse, ending in a Big Crunch.

D) The expansion of the universe is accelerating, due to an unknown cause known as dark energy.

E) Rotational measurements of our galaxy and others demonstrated the existence of dark matter.

Difficulty: E

Section: 44-4

Learning Objective 44.4.9

59. Baryonic matter (protons and neutrons) comprises what fraction of the total energy of the universe?

A) about 1%

B) about 4%

C) about 23%

D) about 73%

E) almost 100%

Difficulty: E

Section: 44-4

Learning Objective 44.4.10