13C Physics - self-authored Topic 6 MCQs

1. Quarks can exist on their own

2. Quarks can exist in pairs

3. Quarks can be in triplets

(MC)

• Only 1. is true

• Only 2. is true

• 2. and 3. are true

• All are true

Which is false (or at least, not always true)? (MC)

• The higher the binding energy of a nucleus, the more stable it is

• When a nucleus decays its binding energy per nucleon increases?

• Increasing binding energy per nucleon releases energy

• The total mass of separated nucleons is greater than the mass of the nucleus

Which is true? (MC)

• The moderator decreases the rate of reaction by slowing down neutrons

• The moderator increases rate of reaction by speeding up neutrons

• The moderator decreases rate of reaction by absorbing neutrons

• The moderator increases rate of reaction by slowing down neutrons

• A: activity

  A0: original activity

  lambda : decay constant

  t: half life

• A: activity

  A0: original activity

  lambda : decay constant

  t: time

• A: original activity

  A0: activity

  lambda : wavelength

  t: time

• A: original activity

  A0: activity

  lambda : wavelength

  t: half life

The half life of uranium-238 is 4.5 billion years. 1.5% of the material has decayed into lead-206. How long has the material been radiating for? (PR)

• 300 million years

• 98 million years

• 1 billion years

Which is not a major contributor to background radiation? (PR)

• Cosmic rays

• Fallout from nuclear bombs

• Buildings

Which of the following best describes the decay constant? (PR)

• Reciprocal of half life

• Rate of decay

• Constant of proportionality (links rate of decay to number of undecayed nuclei)

What was observed in Rutherford's scattering experiment? (GL)

• Most of the alpha particles were deflected backwards

• Most of the alpha particles passed straight through the gold atoms but some were deflected backwards

• Most of the alpha particles were slightly deflected

• All alpha particles passed through the gold atoms

Sodium-24 (Z=11) decays into the stable nuclide magnesium-24 (Z=12). What type of decay is this? (GL)

• beta plus

• gamma

• beta minus

• alpha

Which of these is the quark composition of a meson? (GL)

• Three quarks

• Quark and anti-quark pair

• Two up quarks, one down quark

• One up quark, two down quarks