Deck 30: Particle Physics

Question 1

What combination of quarks produces a neutron and what are the electric charges on these quarks,expressed in terms of e?

Answer 1

udd,with charges +2/3 e,-1/3 e,and -1/3 e

Question 2

Inside the nucleus,the strongest of the four fundamental forces is

A)the weak nuclear force.
B)the electromagnetic force.
C)the gravitational force.
D)the strong nuclear force.

Answer 2

D

Question 3

A stable nucleus contains many protons very close to each other,all positively charged.Why do the protons not fly apart due to mutual Coulomb repulsion?

A)An attractive nuclear force in the nucleus counteracts the effect of the Coulomb forces.
B)There are an equal number of electrons in the nucleus which neutralize the protons.
C)The neutrons in the nucleus shield the protons from each other.
D)The Coulomb force does not operate within nuclei.
E)The gravity of the protons and neutrons overcomes their repulsion at such close distances.

Answer 3

A

Question 4

The two strongest forces that protons in a nucleus exert on each other are

A)the weak nuclear and electromagnetic forces.
B)the weak nuclear and the gravitational forces.
C)the electrostatic and the gravitational forces.
D)the strong nuclear and the electrostatic forces.

Question 5

Elementary particles that experience the weak nuclear force but not the strong nuclear force are called

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

Question 6

Inside the nucleus,the weakest of the four fundamental forces is

A)the weak nuclear force.
B)the electromagnetic force.
C)the gravitational force.
D)the strong nuclear force.

Question 7

The proton is made up of which one of the following quark combinations (up,down,strange,charm,top,bottom)?

A)uud
B)ddu
C)udd
D)ttb
E)bst

Question 8

Which of the following statements about hadrons are correct? (There may be more than one correct choice.)

A)Hadrons are composed of leptons.
B)All hadrons are composed of quarks.
C)All hadrons interact by the strong nuclear force.
D)Electrons, protons, and neutrons are commonly-occurring hadrons.
E)Protons and neutrons are hadrons, but the electron is not.

Question 9

How many quarks are in a tritium isotope, H?

A)2
B)3
C)4
D)6
E)9

Question 10

How does the range of an exchange force depend on the mass of the exchange particle?

A)The range is longer for a massive exchange particle than for a light exchange particle.
B)The range is shorter for a massive exchange particle than for a light exchange particle.
C)The range does not depend on the mass of the exchange particle.

Question 11

The neutron is made up of which one of the following quark combinations (up,down,strange,charm,top,bottom)?

A)uud
B)ddu
C)udd
D)ttb
E)bst

Question 12

The main reason that there is a limit to the size of a stable nucleus is

A)the limited range of the gravitational force.
B)the short range nature of the strong nuclear force.
C)the weakness of the gravitational force.
D)the weakness of the electrostatic force.

Question 13

What combination of quarks produces a proton and what are the electric charges on these quarks,expressed in terms of e?

Question 14

How many quarks are in a deuteron, H?

A)2
B)3
C)4
D)6
E)9

Question 15

What are the possible charges of a quark (not an antiquark)?

A)-e, 0, e
B)-2/3 e, -1/3 e, +1/3 e, +2/3 e
C)-2/3 e, +1/3 e
D)-1/3 e, +2/3 e
E)-1/3 e, +1/3 e

Question 16

Which of the following particles are leptons? (There may be more than one correct choice.)

A)protons
B)neutrons
C)electrons
D)photons
E)quarks

Question 17

Leptons can interact by which of the following forces?

A)strong nuclear force, weak nuclear force, electromagnetic force, gravitation
B)strong nuclear force, weak nuclear force, electromagnetic force
C)weak nuclear force, electromagnetic force, gravitation
D)strong nuclear force, weak nuclear force
E)strong nuclear force, electromagnetic force, gravitation

Question 18

Which of the following statements is not true of the strong nuclear force?

A)The nuclear force has a short range, of the order of nuclear dimensions.
B)For two protons that are very close together, the nuclear force and the electric force have about the same magnitudes.
C)The nuclear force does not depend on charge.
D)A nucleon in a large nucleus interacts via the nuclear force only with nearby nucleons, not with ones far away in the nucleus.
E)The nuclear force affects both neutrons and protons.

Question 19

Which of the following particles (or groups of particles)are made up of quarks?

A)protons, neutrons, and electrons
B)electrons and neutrinos
C)photons
D)protons and neutrons
E)All particles except for photons are made up of quarks.

Question 20

Which of the following particles are not made up of quarks? (There could be more than one correct choice.)

A)alpha particle
B)electron
C)proton
D)positron
E)neutron

Question 21

An electron and a positron,both essentially at rest,annihilate each other,emitting two identical photons in the process.What is the wavelength of these photons? The mass of an electron or positron is 9.11 × 10^-31 kg.(h = 6.626 × 10^-34 J ∙ s,c = 3.00 × 10⁸ m/s)

A)1.21 × 10^-12 pm
B)1.73 pm
C)2.42 pm
D)3.07 pm
E)3.46 pm