Key term
OCR A-Level Physics A H556
Practical Skills in the Written Papers
The Practical Endorsement
Topic overviewAnalogue and digital measuring instrumentsImproving accuracy with repeat timing, fiducial markers and plumb linesTiming, calipers and micrometersConstructing and testing circuitsSignal generators and oscilloscopesGenerating and measuring wavesData loggers, modelling software and ionising radiation
Physical Quantities and Units
Making Measurements and Analysing Data
Nature of Quantities
Motion
Forces in Action
Work, Energy and Power
Materials
Newton’s Laws of Motion and Momentum
Charge and Current
Energy, Power and Resistance
Electrical Circuits
Waves
Topic overviewProgressive waves and their propertiesThe wave equationReflection, refraction and diffractionWave graphs and intensityThe electromagnetic spectrumPolarisationRefraction and refractive indexCritical angle and total internal reflectionThe principle of superpositionInterference, coherence and path differenceTwo-source interference, Young's double-slit experiment and the diffraction gratingForming stationary wavesStationary waves on strings and in air columnsMeasuring the speed of soundNode spacing, amplitude and phase in stationary wavesHarmonics and the fundamental mode
Quantum Physics
Thermal Physics
Topic overviewThermal equilibrium and absolute temperatureThe kinetic model of solids, liquids and gasesBrownian motion and internal energySpecific heat capacityMeasuring specific heat capacitySpecific latent heatMeasuring specific latent heatMoles, the Avogadro constant and kinetic theoryGas laws, the ideal gas equation and r.m.s. speedMaxwell-Boltzmann distribution, Boltzmann constant and internal energy
Oscillations
Gravitational Fields
Astrophysics and Cosmology
Topic overviewThe solar system and the birth of a starThe death of a low-mass starSupernovae, neutron stars and black holesThe Hertzsprung-Russell diagramEnergy levels and emission spectraAbsorption spectra and spectral linesPhoton energy and the diffraction gratingWien's law and Stefan's lawAstronomical distances, parallax and the cosmological principleDoppler shift and Hubble's lawThe expanding universe and the Big BangEvidence for the Big Bang and dark energy
Capacitors
Topic overviewCapacitance and charging a capacitorCapacitors in seriesCapacitors in parallel and combined circuitsEnergy stored by a capacitorCharging and discharging through a resistorInvestigating capacitor dischargeThe time constantIterative modelling, exponential decay and the constant-ratio property
Electric Fields
Electromagnetism
Nuclear and Particle Physics
Topic overviewAlpha-particle scattering and the nuclear modelProton number, nucleon number and isotopesThe strong nuclear force and nuclear radiusParticles, antiparticles and hadronsLeptons and the quark modelQuark composition and chargesBeta decay in the quark modelRadioactive decay and the three radiationsNuclear decay equationsActivity, decay constant and half-lifeExponential decay and radioactive datingMass-energy equivalenceAnnihilation, mass defect and binding energyBinding energy per nucleon and induced fissionThe fission reactor and nuclear wasteNuclear fusion and balancing nuclear equations
Waves
- 16 subtopics
- 45 things to know
- Papers 2 and 3
What Waves covers
The largest topic on the course: what a progressive wave is, the electromagnetic spectrum, polarisation, refraction and total internal reflection, interference and the double-slit experiment, and stationary waves and harmonics.
Where it is assessed
Papers 2 and 3
Electrons, waves and photons, examined on Exploring Physics and Unified Physics.
Check the OCR specification ↗The 16 subtopics
Each one has its own page.
- Progressive waves and their propertiesRecall questions on transverse and longitudinal waves, displacement, amplitude, wavelength, period, phase difference, frequency and wave speed, and what a progressive wave transfers.Open →
- The wave equationRecall questions on finding period and frequency from an oscilloscope trace, f = 1/T, the wave equation v = fλ and calculations with both.Open →
- Reflection, refraction and diffractionRecall questions on defining reflection, refraction and diffraction, when diffraction becomes significant, and demonstrating reflection, refraction and diffraction of water waves in a ripple tank.Open →
- Wave graphs and intensityRecall questions on displacement-distance and displacement-time graphs, representing longitudinal waves graphically, and wave intensity: its equation, units, calculation and dependence on amplitude.Open →
- The electromagnetic spectrumRecall questions on the structure and speed of electromagnetic waves, the order of the electromagnetic spectrum by frequency, and the typical wavelengths of radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays.Open →
- PolarisationRecall questions on polarisation and plane polarised waves, why only transverse waves can be polarised, and demonstrating polarisation with polarising filters, crossed polarisers and microwaves with a metal grille.Open →
- Refraction and refractive indexRecall questions on refraction and refractive index, n = c/v, the direction light bends between media, investigating refraction with rectangular and semi-circular blocks, and Snell's law.Open →
- Critical angle and total internal reflectionRecall questions on the critical angle, its relationship to refractive index, total internal reflection and the conditions for it, and investigating it with a semi-circular block.Open →
- The principle of superpositionRecall questions on the principle of superposition, finding a resultant wave graphically, in-phase and antiphase superposition, interference, and the waves used to demonstrate superposition including microwaves.Open →
- Interference, coherence and path differenceRecall questions on coherence, path difference and phase difference, the conditions for constructive and destructive interference, and why a single light source is used with a double slit.Open →
- Two-source interference, Young's double-slit experiment and the diffraction gratingRecall questions on two-source interference with sound, microwaves and light, Young's double-slit experiment and its significance, the equation λ = ax/D, measuring a, x and D, and calculating wavelength.Open →
- Forming stationary wavesRecall questions on how a stationary wave forms, and on the similarities and differences against a progressive wave.Open →
- Stationary waves on strings and in air columnsRecall questions on setting up stationary waves on a stretched string and in air columns, boundary conditions, and the node and antinode patterns of the fundamental, second and nth harmonics of a string.Open →
- Measuring the speed of soundRecall questions on the techniques used to determine the speed of sound using stationary waves.Open →
- Node spacing, amplitude and phase in stationary wavesRecall questions on detecting nodes and antinodes, how amplitude and phase differ between stationary and progressive waves, and why adjacent nodes or antinodes are half a wavelength apart.Open →
- Harmonics and the fundamental modeRecall questions on the fundamental and the higher harmonics, and on the frequencies at which they occur.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
What are the phase difference, period and frequency of a wave, and what units is each measured in?
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What is wave speed and its SI unit, and when an oscilloscope is used, what must first be displayed and what is measured to find the period?
Numbers
Define the intensity of a progressive wave and state its equation in terms of power and area.
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What are the SI units of intensity, how does intensity depend on amplitude, and what happens to the intensity if the amplitude doubles?
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Explain why longitudinal waves cannot be polarised, and define a plane polarised wave.
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How do a metal grille and polarising filters demonstrate polarisation, and what happens when two polarising filters are crossed at 90°?
Numbers
Define phase difference and path difference, and state the formula that relates them.
Numbers
Define constructive interference, and state the path difference and phase difference conditions that produce it.
Key term
Under what condition is the double-slit equation valid, and which two distances must be measured to use it?
Numbers
Define a node and an antinode on a stationary wave, and state the phase relationship between points in adjacent segments.
Numbers
In a stationary wave, what are the separations of adjacent antinodes and of adjacent nodes in terms of the wavelength of the progressive wave?
Key term
How is a stationary wave formed, what does λ represent in the formula for antinode separation, and why are adjacent antinodes half a wavelength apart?
Numbers
For the fundamental mode of a stretched string, describe the pattern of nodes and antinodes and state the relationship between string length and wavelength.
Numbers
For a closed tube, describe the node and antinode arrangement and the relationship between tube length and wavelength in the fundamental mode, and state which harmonics it can produce.
Numbers
For an open tube, describe the node and antinode arrangement and the relationship between tube length and wavelength in the fundamental mode, and state which harmonics it can produce.
Key term
Where does visible light sit in the electromagnetic spectrum relative to infrared and ultraviolet?
Who and when
What quantity remains constant when light crosses a boundary between two media, according to the relationship involving refractive index and angle?
Key term
What is varied during an investigation of total internal reflection using a semi-circular block?
Numbers
What phase difference in radians corresponds to a path difference of one wavelength?
Numbers
State the relationship between string length and wavelength for the second harmonic of a stretched string.
Key term
When using an oscilloscope to determine frequency, what must first be displayed?
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Define reflection of a wave.
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State the speed at which all electromagnetic waves travel in a vacuum.
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What is the approximate wavelength range for visible light?
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What happens when unpolarised light passes through two polarising filters whose transmission axes are crossed at 90° to each other?
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Describe how interference patterns are created and detected in a microwave superposition experiment.
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Explain how the resultant wave is determined when superposing two waves graphically.
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What is a stationary (standing) wave?
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In a microwave stationary wave demonstration, what does the microwave transmitter do?
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What boundary condition applies to a stretched string used to demonstrate stationary waves?
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What boundary conditions apply at the ends of a closed tube for stationary sound waves?
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What boundary conditions apply at the ends of an open tube for stationary sound waves?
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Under what condition do diffraction effects become significant?
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What does a progressive wave transfer, and what does it not transfer?
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Why can electromagnetic waves travel through outer space where there is no air?
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State the order of magnitude of wavelengths for radio waves.
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Define refraction.
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Write the rearranged form of Snell's law used to find the angle of refraction.
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What is the resultant amplitude when two waves in antiphase are superposed graphically?
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When two waves that are in phase are superposed, what is the resultant amplitude?
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Name three types of waves that can be used to demonstrate superposition and interference experimentally.
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What happens to microwaves when they reach the metal plate in a stationary wave demonstration?
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How is a stretched string driven to produce stationary waves?
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In a resonance tube experiment to measure the speed of sound, where is the sound source positioned?
Take Waves further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Progressive wave vs Stationary wave
Progressive wave: disturbance transferring energy through space. Stationary wave: fixed pattern formed by superposed opposite waves.
Refraction vs Diffraction
Refraction: direction change caused by wave-speed change. Diffraction: spreading when waves pass an aperture or edge.
Coherent sources vs Incoherent sources
Coherent sources: sources maintaining constant phase difference. Incoherent sources: sources with changing phase difference.
Questions from this topic
Each one with the model answer underneath.
- 1
How are the oscillations of particles oriented relative to the direction of wave propagation in a transverse wave?
Model answer
The oscillations of particles are perpendicular to the direction of wave propagation.
- 2
In a longitudinal wave, what is the relationship between particle oscillation direction and wave propagation direction?
Model answer
The oscillations of particles are parallel to the direction of wave propagation.
- 3
Define displacement in the context of wave motion.
Model answer
Displacement is the distance of a point on the wave from its equilibrium position, measured in metres.
- 4
What is meant by the amplitude of a wave?
Model answer
Amplitude is the maximum displacement of a point on the wave from its equilibrium position.
- 5
Define wavelength.
Model answer
Wavelength is the minimum distance between two points on a wave that are in phase, measured in metres.
- 6
What is the period of a wave?
Model answer
Period is the time taken for one complete oscillation of a point on the wave, measured in seconds.
What is inside Levo
Six ways to work the same material.
Waves revision questions
- What does Waves cover in OCR A-Level Physics A?
- 16 subtopics: progressive waves and their properties, the wave equation, reflection, refraction and diffraction, wave graphs and intensity, the electromagnetic spectrum, polarisation, refraction and refractive index, critical angle and total internal reflection, the principle of superposition, interference, coherence and path difference, two-source interference, young's double-slit experiment and the diffraction grating, forming stationary waves, stationary waves on strings and in air columns, measuring the speed of sound, node spacing, amplitude and phase in stationary waves and harmonics and the fundamental mode. Each one has its own page with questions and model answers.
- How is Waves organised?
- By the OCR H556 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Waves, 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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