Key term
OCR A-Level Physics B H557
Planning
Implementing
Analysis
Evaluation
Practical Skills
Use of Apparatus and Techniques
Fundamental Data Analysis
Imaging and Signalling
Topic overviewReal images and the curvature of wave-frontsLens power and focal lengthThe thin lens equation and the Cartesian conventionLinear magnificationMeasuring the power and focal length of a converging lensImages as arrays of numbersBits, bytes and the information in an imageEnhancing a digital imageWave-forms, frequency and wave speedSampling and digitising an analogue signalNoise, resolution and digital transmissionPolarisation of electromagnetic waves
Sensing
Topic overviewCurrent and the flow of chargePotential difference, e.m.f. and energy transferResistance, conductance and Ohm's lawSeries and parallel combinationsPower and energy in electric circuitsInternal resistance and e.m.f.Kirchhoff's laws and conservation in circuitsResistivity and conductivityCharge carrier number density in metals, semiconductors and insulatorsCurrent-potential difference characteristics and circuit componentsThe potential dividerSensing circuits and calibration
Mechanical Properties of Materials
Topic overviewElastic and plastic deformation and fractureHooke's law and force-extension graphsElastic strain energyStress, strain and the Young modulusMeasuring the Young modulus and fracture stress of a metalDescribing and comparing materialsMetals, ceramics and polymersDirect evidence for the size and spacing of particles
Waves and Quantum Behaviour
Topic overviewWaves, phase and superpositionStanding waves on stringsStanding waves in air columns and the speed of soundRefraction, refractive index and Snell's lawTwo-slit interferenceDiffraction at a narrow apertureThe diffraction gratingMeasuring the wavelength of lightPhotons and the quantum E = hfEvidence that photons exchange energy in quantaQuantum behaviour: phasors and probability of arrivalElectron diffraction and the de Broglie wavelength
Space, Time and Motion
Topic overviewScalars, vectors and their representationResolving and adding vectorsDescribing motion: displacement, velocity and accelerationMotion graphsThe kinematic equations for constant accelerationProjectiles and motion in two dimensionsMeasuring motion in the laboratoryDetermining the acceleration of free fallNewton's laws of motionTerminal velocity and resistive forcesMomentum and impulseConservation of momentum and collisionsWork, energy and its conservationPower and modelling motion in small time steps
Creating Models
Topic overviewCapacitance and charge storageEnergy stored on a capacitorCapacitor discharge and the exponential modelThe time constant of an RC circuitCharging a capacitorInvestigating capacitor charge and dischargeRadioactive decay as a random processActivity, decay constant and half-lifeDetermining the half-life of an isotopeIterative numerical models of exponential changeExponential curves on linear and logarithmic scalesSimple harmonic motion: the defining relationshipSolutions and graphs of simple harmonic motionModelling oscillations step by stepEnergy in simple harmonic motionPeriod of a mass–spring system and a simple pendulumFree and forced vibrations, damping and resonance
Out Into Space
Topic overviewGravitational and kinetic energy changesMotion in a uniform gravitational fieldGravitational force and the radial fieldGravitational field strengthGravitational potential energy in a radial fieldGravitational potential and equipotentialsGraphs and diagrams of gravitational fieldsAngular velocity and motion in a horizontal circleCircular gravitational orbits
Our Place in the Universe
Matter: Very Simple
Topic overviewEnergy transfer and specific thermal capacityFinding specific thermal capacity by an electrical methodIdeal gases and the gas lawsInvestigating the gas laws and absolute zeroMoles, the Avogadro constant and the Boltzmann constantThe equation of state for an ideal gasImpulse and force–time graphsThe kinetic theory of ideal gasesTemperature, average energy per particle and internal energyRandom walk of molecules in a gas
Matter: Hot or Cold
Electromagnetism
Topic overviewMagnetic flux, B-fields and flux linkageElectromagnetic induction: Faraday's and Lenz's lawsGraphs of current, flux and induced e.m.f.The dynamoThe transformerEddy currents and real transformersForces on current-carrying conductorsMagnetic circuits, permeance and machine designInvestigating induction, flux density and transformers
Charge and Field
Topic overviewThe uniform electric fieldRadial fields and the inverse square lawElectric potential and potential energyField and potential graphsField lines and equipotential surfacesThe electronvolt and accelerating chargesMillikan's experiment and the discreteness of chargeMoving charges in magnetic fieldsComparing electric and gravitational fields
Probing Deep Into Matter
Topic overviewParticle accelerators and high-energy beamsScattering and the nuclear atomPaths of scattered particles and closest approachDiscrete energy levels in atomsElectron standing waves and the confined electronQuarks, hadrons and leptonsConservation laws and nuclear equationsCharged particles in detectors and magnetic fieldsRelativistic energy and the relativistic factor
Ionising Radiation and Risk
Topic overviewThe nature of ionising radiationsEffects on living tissue and radiation safetyAbsorbed dose, effective dose and riskBinding energy and nuclear stabilityThe Nuclear Valley and modes of decayFission, fusion and nuclear powerActivity, half-life and the decay constantInvestigating absorption and half-life
Waves and Quantum Behaviour
- 12 subtopics
- 36 things to know
- Components 01, 02 and 03
What Waves and Quantum Behaviour covers
Waves and Quantum Behaviour 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 waves, phase and superposition, standing waves on strings, standing waves in air columns and the speed of sound, refraction, refractive index and Snell's law, two-slit interference, diffraction at a narrow aperture, the diffraction grating, measuring the wavelength of light, photons and the quantum E = hf, evidence that photons exchange energy in quanta, quantum behaviour: phasors and probability of arrival and electron diffraction and the de Broglie wavelength.
Where it is assessed
Components 01, 02 and 03
Every module can be assessed on any of the three papers.
Check the OCR specification ↗The 12 subtopics
Each one has its own page.
- Waves, phase and superpositionRecall questions on the principle of superposition, amplitude, phase and phase difference, path difference, coherent sources and why two lamps give no fringes, the path difference conditions for constructive and destructive interference, intensity and its link to amplitude, and v = fλ for sound.Open →
- Standing waves on stringsRecall questions on how standing waves form on a string, nodes and antinodes and their spacing, why no energy is transferred, displacement and phase within and between loops, fundamental and harmonic wavelengths, calculating wave speed, counting nodes, the effect of tension, why only certain frequencies resonate, and driving a string with a vibration generator.Open →
- Standing waves in air columns and the speed of soundRecall questions on how an air column resonates, where nodes and antinodes fall, using two resonance positions rather than one, oscilloscope frequency measurements, and a closed tube's resonance ratio.Open →
- Refraction, refractive index and Snell's lawRecall questions on what changes and what stays the same as light enters glass, the wave explanation of bending, Snell's law calculations, ray-box measurements, and dispersion of colours.Open →
- Two-slit interferenceRecall questions on the two-slit fringe pattern, why bright, dark and central fringes appear, why one source lights both slits, how slit separation, screen distance and colour change the fringe spacing, nλ = d sin θ and x = λD/d, the small-angle approximation, covering one slit, narrow slits, and white-light fringes.Open →
- Diffraction at a narrow apertureRecall questions on when spreading at a gap is greatest, water waves through wide and narrow gaps, the single-slit pattern, angular spread, and why apertures limit a telescope or camera.Open →
- The diffraction gratingRecall questions on what a diffraction grating is and why its maxima are sharp, nλ = d sin θ and the order of a maximum, slit spacing from lines per millimetre, angles and the highest observable order, zero-order and white-light spectra, resolving close wavelengths, finding the slit spacing with sodium light, parallel beams, and overlapping orders.Open →
- Measuring the wavelength of lightRecall questions on the double-slit arrangement, why ten fringe spacings and a distant screen help, what limits accuracy, gratings and higher orders, angles measured both sides, and laser safety.Open →
- Photons and the quantum E = hfRecall questions on photons and E = hf, the value of the Planck constant, E = hc/λ, the electronvolt and converting between joules and electronvolts, ultraviolet against infrared photons, X-ray photon energy, the photon rate from a laser, why light's energy arrives in quanta, and what sets a beam's brightness.Open →
- Evidence that photons exchange energy in quantaRecall questions on threshold frequency, work function and φ = hf₀, the photoelectric equation hf = φ + Eₖ(max) and calculations with it, why intense light below threshold frees no electrons, why the wave model fails, line emission spectra, determining the Planck constant with LEDs, and the limits of the particle and wave models of light.Open →
- Quantum behaviour: phasors and probability of arrivalRecall questions on phasors and their rate of rotation, probability of arrival from the resultant phasor, trip time and phasor direction, why light travels in straight lines, paths of stationary time, bright and dark two-slit fringes, photons arriving one at a time, blocking alternate zones, wide slits, and how phasors avoid choosing between wave and particle.Open →
- Electron diffraction and the de Broglie wavelengthRecall questions on the ring pattern from graphite and what it shows, de Broglie wavelengths of electrons, protons and everyday objects, the effect of accelerating voltage, and microscope resolution.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
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How is the refractive index of a rectangular glass block measured with a ray box and a protractor?
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State the grating equation and define each term in it.
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How is the wavelength of laser light measured using a double slit?
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State the photoelectric equation and explain what each term represents.
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Define the amplitude of a wave.
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What is a node on a standing wave?
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Describe what is seen on a distant screen when coherent light passes through two narrow slits.
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Define diffraction.
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What is a photon?
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What is a phasor?
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What is observed when a beam of electrons passes through a thin film of polycrystalline graphite?
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What is meant by the phase of an oscillation?
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What is an antinode on a standing wave?
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State the wavelength of the lowest resonant sound in a tube of length l closed at one end.
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What happens to the speed of light when it passes from air into glass?
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Explain why bright fringes appear in a two-slit pattern.
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Under what condition is diffraction at an aperture most pronounced?
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What is a diffraction grating?
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Why is the width of ten fringe spacings measured rather than one in the double-slit experiment?
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How is the energy of a photon related to the frequency of the radiation?
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Define the work function of a metal.
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How is the probability that a photon arrives at a particular point obtained?
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Why does electron diffraction through graphite give rings rather than separate spots?
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Two points on a progressive wave are half a wavelength apart. What is the phase difference between them in radians?
Evaluation
How far apart are adjacent nodes on a standing wave?
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Why is the difference between two resonance positions used rather than the first resonance alone?
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Explain, using the wave model, why light bends towards the normal on entering glass.
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Explain why dark fringes appear in a two-slit pattern.
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Describe the pattern produced when laser light passes through a single narrow slit onto a screen.
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Explain why a grating produces sharp bright maxima rather than broad fringes.
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Why should the screen be placed as far from the double slit as the room allows?
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State the value and unit of the Planck constant.
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Define the threshold frequency for a metal surface.
Numbers
How many rotations does a phasor make along a path 1.5 μm long for light of wavelength 500 nm?
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State the de Broglie relationship and define its terms.
Take Waves and Quantum Behaviour further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Path difference vs Phase difference
Path difference: the extra distance one wave has travelled compared with the other when they meet, measured in metres or in wavelengths. Phase difference: How far through its cycle one oscillation is ahead of another, measured as an angle, one whole wavelength of extra distance corresponding to 2π radians.
Node vs Antinode
Node: a point on a standing wave where the two travelling waves are always in antiphase, so the displacement there is zero at all times. Antinode: A point on a standing wave where the two travelling waves are always in phase, so the oscillation there reaches maximum amplitude.
Interference vs Diffraction
Interference: the superposition of waves arriving from two or more coherent sources, reinforcing where they arrive in phase and cancelling where they arrive in antiphase. Diffraction: The spreading out of a wave as it passes through an aperture or round the edge of an obstacle, greatest when the opening is comparable with the wavelength.
Questions from this topic
Each one with the model answer underneath.
- 1
What does the principle of superposition state about two waves meeting at a point?
Model answer
Where two waves meet, the resultant displacement at any instant is the vector sum of the displacements each wave would produce on its own.
- 2
Define the amplitude of a wave.
Model answer
The amplitude is the maximum displacement of the medium or field from its equilibrium position.
- 3
What is meant by the phase of an oscillation?
Model answer
The phase is how far through a complete cycle the oscillation has advanced, normally quoted as an angle in degrees or radians.
- 4
Two points on a progressive wave are half a wavelength apart. What is the phase difference between them in radians?
Model answer
The phase difference between them is π radians.
- 5
What phase difference in degrees corresponds to a path difference of one whole wavelength?
Model answer
A path difference of one wavelength corresponds to a phase difference of 360°.
- 6
Define the path difference between two waves arriving at the same point.
Model answer
The path difference is the difference between the distances the two waves have travelled from their sources to that point.
What is inside Levo
Six ways to work the same material.
Waves and Quantum Behaviour revision questions
- What does Waves and Quantum Behaviour cover in OCR A-Level Physics B?
- 12 subtopics: waves, phase and superposition, standing waves on strings, standing waves in air columns and the speed of sound, refraction, refractive index and snell's law, two-slit interference, diffraction at a narrow aperture, the diffraction grating, measuring the wavelength of light, photons and the quantum e = hf, evidence that photons exchange energy in quanta, quantum behaviour: phasors and probability of arrival and electron diffraction and the de broglie wavelength. Each one has its own page with questions and model answers.
- How is Waves and Quantum Behaviour organised?
- By the OCR H557 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Waves and Quantum Behaviour, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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