Nuclear Physics Quiz

What is the purpose of the graphite used as a moderator in a nuclear reactor?

• to absorb all the heat produced

• to decrease the neutron speeds

• to absorb the α and γ radiations

• to prevent the reactor from going critical

What is the mass difference of the ( ^{7}_{3} )Li nucleus?

• 0.93912 u

• 0.04051 u

• 0.04077 u

• 0.04216 u

The nuclear fuel in a reactor decreases in mass at a rate of 6.0 x 10^-6 kg per hour. What is the maximum possible power output of the reactor?

• 6.0 x 10^6 watts

• 6.0 x 10^5 watts

• 5.4 x 10^5 watts

• 5.4 x 10^6 watts

Which one of the following statements is true regarding induced fission in a thermal reactor?

• To sustain the reaction a large number of neutrons is required per fission.

• The purpose of the moderator is to absorb all the heat produced.

• The neutrons required for induced fission of 235 92 U should be slow neutrons.

• The purpose of the control rods is to slow down neutrons to thermal speeds.

What is the effect of fully inserting the control rods into the core of a thermal nuclear reactor?

• The number of fission neutrons and the average kinetic energy of fission neutrons are both reduced.

• The number of fission neutrons is reduced, but the average kinetic energy of fission neutrons remains unchanged.

• The number of fission neutrons remains unchanged, but the average kinetic energy of fission neutrons is reduced.

• The number of fission neutrons and the average kinetic energy of fission neutrons remain unchanged.

What is the binding energy of the nucleus 238 92 U?

• This question requires calculation and cannot be answered without additional information.

• This question requires calculation and cannot be answered without the mass of 238 92 U.

• This question requires calculation and cannot be answered without the atomic number of uranium.

• This question requires calculation and cannot be answered without the mass defect.

What is the mass of a ^{238}U nucleus in atomic mass units (u)?

• 1685 u

• 1732 u

• 1755 u

• 238.05076 u

Why is a moderator required in a thermal nuclear reactor?

• To prevent overheating of the nuclear core

• To absorb surplus uranium nuclei

• To shield the surroundings from gamma radiation

• To reduce the kinetic energy of fission neutrons

The fusion of two deuterium nuclei produces a nuclide of helium plus a neutron and liberates 3.27 MeV of energy. How does the mass of the two deuterium nuclei compare with the combined mass of the helium nucleus and neutron?

• It is 5.8 x 10^-30 kg greater before fusion.

• It is 5.8 x 10^-30 kg greater after fusion.

• It is 5.8 x 10^-36 kg greater before fusion.

• It is 5.8 x 10^-36 kg greater after fusion.

What is the binding energy per nucleon of the beryllium nucleus, ^{7}Be, given its mass is 7.01473 u?