Question 1

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

Accepted Answer

A) Energy 
B) Lepton number 
C) Electric charge 
D) Linear momentum 
E) Angular momentum 
A) Energy 
B) Lepton number 
C) Electric charge 
D) Linear momentum 
E) Angular momentum E

Question 2

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

Accepted Answer

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 
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 E

Question 3

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

Accepted Answer

A) Energy 
B) Baryon number 
C) Linear Momentum 
D) Angular momentum 
E) None of the above 
A) Energy 
B) Baryon number 
C) Linear Momentum 
D) Angular momentum 
E) None of the above D

Question 4

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

Accepted Answer

A) a proton 
B) an omega minus 
C) a sigma 
D) an antiparticle 
E) none of these 
A) a proton 
B) an omega minus 
C) a sigma 
D) an antiparticle 
E) none of these

Question 5

All particles with spin angular momentum

Accepted Answer

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 
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

Question 6

Which of the following statements is correct?

Accepted Answer

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. 
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.

Question 7

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

Accepted Answer

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 
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

Question 8

The quark content of a proton is:

Accepted Answer

A) uuu 
B) uud 
C) udd 
D) ddd 
E) uds 
A) uuu 
B) uud 
C) udd 
D) ddd 
E) uds

Question 9

The interaction  $\pi$ - + p  $\rightarrow$  K- +    + violates the principle of conservation of:

Accepted Answer

A) baryon number 
B) lepton number 
C) strangeness 
D) angular momentum 
E) none of these 
A) baryon number 
B) lepton number 
C) strangeness 
D) angular momentum 
E) none of these

Question 10

All leptons interact with each other via the:

Accepted Answer

A) strong force 
B) weak force 
C) electromagnetic force 
D) strange force 
E) none of these 
A) strong force 
B) weak force 
C) electromagnetic force 
D) strange force 
E) none of these

Question 11

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:

Accepted Answer

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 
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

Question 12

A particle with spin angular momentum   is called a:

Accepted Answer

A) lepton 
B) hadron 
C) fermion 
D) boson 
E) electron 
A) lepton 
B) hadron 
C) fermion 
D) boson 
E) electron

Question 13

Messenger particles of the electromagnetic interaction are called:

Accepted Answer

A) gluons 
B) photons 
C) W and Z 
D) gravitons 
E) pions 
A) gluons 
B) photons 
C) W and Z 
D) gravitons 
E) pions

Question 14

A particle with spin angular momentum   is called a:

Accepted Answer

A) lepton 
B) hadron 
C) fermion 
D) boson 
E) electron 
A) lepton 
B) hadron 
C) fermion 
D) boson 
E) electron

Question 15

A particle can decay to particles with greater rest mass:

Accepted Answer

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 
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

Question 16

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

Accepted Answer

A) 105 y 
B) 1010 y 
C) 1015 y 
D) 1020 y 
E) 1025 y 
A) 105 y 
B) 1010 y 
C) 1015 y 
D) 1020 y 
E) 1025 y

Question 17

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

Accepted Answer

A) about 1% 
B) about 4% 
C) about 23% 
D) about 73% 
E) almost 100% 
A) about 1% 
B) about 4% 
C) about 23% 
D) about 73% 
E) almost 100%

Question 18

A certain process produces baryons that decay with a lifetime of 4 * 10-24 s.The decay is a result of:

Accepted Answer

A) the gravitational interaction 
B) the weak interaction 
C) the electromagnetic interaction 
D) the strong interaction 
E) some combination of the above 
A) the gravitational interaction 
B) the weak interaction 
C) the electromagnetic interaction 
D) the strong interaction 
E) some combination of the above

Question 19

Strangeness is conserved in:

Accepted Answer

A) all particle decays 
B) no particle decays 
C) all weak particle decays 
D) all strong particle decays 
E) some strong particle decays 
A) all particle decays 
B) no particle decays 
C) all weak particle decays 
D) all strong particle decays 
E) some strong particle decays

Question 20

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?

Accepted Answer

A) Charge 
B) Linear momentum 
C) Angular momentum 
D) Energy 
E) None of the above 
A) Charge 
B) Linear momentum 
C) Angular momentum 
D) Energy 
E) None of the above

Exam 43: Quarks, Leptons, and the Big Bang

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

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

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

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

All particles with spin angular momentum

Which of the following statements is correct?

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

The quark content of a proton is:

The interaction π\piπ - + p →\rightarrow→ K- + + violates the principle of conservation of:

All leptons interact with each other via the:

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 particle with spin angular momentum is called a:

Messenger particles of the electromagnetic interaction are called:

A particle with spin angular momentum is called a:

A particle can decay to particles with greater rest mass:

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

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

A certain process produces baryons that decay with a lifetime of 4 * 10-24 s.The decay is a result of:

Strangeness is conserved in:

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?

Measurement

Motion Along a Straight Line

Vectors

Motion in Two and Three Dimensions

Force and Motion

Force and Motion

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Gravitation

Fluids

Oscillations

Waves

Waves

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Coulombs Law

Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference 1

Diffraction

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Energy From the Nucleus

Filters

The interaction $\pi$ ^- + p $\rightarrow$ K^- + $The interaction \pi <sup>-</sup> + p \rightarrow K<sup>-</sup> + <sup>+</sup> violates the principle of conservation of:$ ⁺ violates the principle of conservation of:

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