Probing Deep into Matter | OCR A-Level Physics B (Advancing Physics) (H557)
Probing Deep into Matter
- 121 questions
- 9 subtopics
- The physics content, examined on all three papers
- Component 01, Component 02 and Component 03
Probing Deep Into Matter is examined in all three written papers — the specification states that Components 01, 02 and 03 each assess content from across all the teaching modules, so nothing is confined to one paper.
It covers particle accelerators and high-energy beams, scattering and the nuclear atom, paths of scattered particles and closest approach, discrete energy levels in atoms, electron standing waves and the confined electron, quarks, hadrons and leptons, conservation laws and nuclear equations, charged particles in detectors and magnetic fields and relativistic energy and the relativistic factor.
Sample questions from Probing Deep into Matter
Answer each one closed book first, then open the answer.
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Particle accelerators and high-energy beams
What is the role of magnetic fields in a ring accelerator?
Show the answer
Magnetic fields provide the centripetal force through F = qvB that bends the beam round the ring, and further magnets focus the beam so it stays narrow. -
Scattering and the nuclear atom
What conclusion follows from a few alpha particles being deflected through large angles?
Show the answer
The positive charge and nearly all the mass of the atom are concentrated in a very small central region, because only a large charge and mass in a tiny volume could reverse a fast alpha particle. -
Paths of scattered particles and closest approach
Calculate the charge on a gold nucleus, which has 79 protons.
Show the answer
The charge is 79 × 1.60 × 10⁻¹⁹ = 1.26 × 10⁻¹⁷ C. -
Discrete energy levels in atoms
Calculate the frequency of the photon emitted in a transition of energy 2.1 eV.
Show the answer
The energy is 2.1 × 1.60 × 10⁻¹⁹ = 3.36 × 10⁻¹⁹ J, so f = ΔE/h = 3.36 × 10⁻¹⁹ ÷ 6.63 × 10⁻³⁴ = 5.1 × 10¹⁴ Hz. -
Electron standing waves and the confined electron
Calculate the momentum of an electron whose de Broglie wavelength is 2.0 × 10⁻¹⁰ m.
Show the answer
p = h/λ = 6.63 × 10⁻³⁴ ÷ 2.0 × 10⁻¹⁰ = 3.3 × 10⁻²⁴ N s. -
Quarks, hadrons and leptons
What is a hadron?
Show the answer
A hadron is a particle built from quarks that feels the strong interaction, and protons and neutrons are the familiar examples. -
Conservation laws and nuclear equations
Write the equation for the beta-minus decay of carbon-14.
Show the answer
¹⁴₆C → ¹⁴₇N + ⁰₋₁e + ν̄ₑ, so the product is nitrogen-14 together with an electron and an electron antineutrino. -
Charged particles in detectors and magnetic fields
A singly charged particle leaves a track of radius 0.25 m in a field of flux density 1.5 T. Calculate its momentum.
Show the answer
p = qBr = 1.60 × 10⁻¹⁹ × 1.5 × 0.25 = 6.0 × 10⁻²⁰ N s.
The 9 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Particle accelerators and high-energy beams | Recall questions on why probing small structures needs high energy, how a linear accelerator works and why its voltage alternates, magnets and vacuum in a ring, and creating new particles. | 13 |
| Scattering and the nuclear atom | Recall questions on the alpha-particle scattering arrangement, what most particles and a few particles did and what each shows, why a vacuum, a thin foil and gold were used, the sizes of atoms and nuclei and their volume ratio, the model it overturned, the negligible effect of electrons, high-energy electron scattering, and the nuclear atom as a model. | 14 |
| Paths of scattered particles and closest approach | Recall questions on paths near and straight at a nucleus, the energy exchange on approach, calculating a closest approach, why it only bounds the nuclear radius, and how scattering varies with angle. | 13 |
| Discrete energy levels in atoms | Recall questions on energy levels and the evidence of line spectra, ΔE = hf, frequency and wavelength calculations for a transition, absorption against emission spectra, electron collisions as evidence, electrons below the excitation energy, ionisation energy, negative energy values, ground and excited states, excitation against ionisation, and exciting an atom with a 10.4 V electron. | 14 |
| Electron standing waves and the confined electron | Recall questions on why confinement gives discrete energies, the allowed wavelengths and resulting momentum and energy, nodes in higher states, why an atom has a definite size, and the model's limits. | 12 |
| Quarks, hadrons and leptons | Recall questions on the quark compositions and charges of protons, neutrons and antiprotons, the charges of up and down quarks, hadrons, leptons and gluons, antiparticles and the positron, lepton numbers, neutrinos and why they are hard to detect, why free quarks are never seen, and beta-minus decay at quark level. | 15 |
| Conservation laws and nuclear equations | Recall questions on the quantities that must balance, how alpha, beta and gamma emission change a nucleus, decay equations, annihilation and pair production, and why a further particle was proposed. | 14 |
| Charged particles in detectors and magnetic fields | Recall questions on why tracks curve and what the curvature direction reveals, momentum from a track radius, tracks that spiral or appear from nowhere, invisible neutral particles, and charge-to-mass ratios. | 12 |
| Relativistic energy and the relativistic factor | Recall questions on rest energy from rest mass, electron and proton values in MeV, evaluating the factor at high speeds, total and kinetic energy, and why no massive particle reaches light speed. | 14 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
OCR A-Level Physics B (Advancing Physics) Active Recall Guide
Every topic, not just this one. 2,455 questions with their answers.