Key term
OCR GCSE Combined Science Physics J250
Electricity
Topic overviewCharge, and producing static electricityTransfer of electrons in charging and dischargingCurrent as a rate of flow of chargeCharge, current and timeSeries and parallel circuits, and circuit symbolsCurrent, potential difference and resistanceResistors whose resistance changes, and investigating themLinear and non-linear circuit elements from graphsNet resistance in series and parallelCircuits for measurement, and electrical power
Energy
Topic overviewConservation of energy, and energy storesEnergy changes on heating, and calculating themEnergy of a moving body, a spring and a raised objectDissipation, and energy transfer in domestic devicesPower ratings, efficiency, and increasing itReducing unwanted energy transfer, and the rate of cooling
Forces
Topic overviewMeasuring distance and time, and calculating speedConverting units, and ratesVectors and scalars in motionDistance-time and velocity-time graphsAverage speed, and the equations of uniform motionHow objects interact, and forces as vectorsNewton's first lawResolving forces, and free body diagramsResultant forces, and balanced forcesNewton's second law, and inertiaMomentum and its conservationWork done, and stored energyPower, and Newton's third lawCircular motion and changing velocityStretching, bending and compressing; elastic and plasticForce and extension, linear and non-linearThe spring constant, and work done in stretchingGravitational fields, weight and free fallCalculations with weight and gravitational field strength
Global Challenges
Topic overviewTypical speeds and everyday accelerationsReaction time, stopping distance and the dangers of large decelerationsStopping distance, acceleration and collision force calculationsEnergy resources, and trends in their useThe national grid, and step-up and step-down transformersWhy the national grid is efficient, and power in a transformerMains electricity: a.c., d.c. and the domestic supplyLive, neutral and earth wires, and electrical danger
Magnetism and Magnetic Fields
Matter
Topic overviewHow the atomic model changed, and the structure of the atomThe size of atoms, and defining densityDensity of the states of matter, and density calculationsConservation of mass in changes of stateHeating a system, and specific heat capacityCalculations with specific heat capacity and latent heatGas molecules, temperature and pressure
Radioactivity
Waves in Matter
Topic overviewAmplitude, wavelength, frequency and periodThe wave equationTransverse and longitudinal wavesModelling waves with ripples and soundElectromagnetic waves as transverse, and energy transferFrequency and wavelength across the spectrumWhat our eyes detect, and light as an electromagnetic waveUses of electromagnetic wavesHazards of ultraviolet, X-rays and gamma raysProducing and receiving radio wavesAbsorption, transmission, refraction and reflectionInvestigating reflection and refraction of light
Waves in Matter
- 12 subtopics
- 34 things to know
- Paper 12 (Physics)
What Waves in Matter covers
Waves in Matter is examined in Paper 12 (Physics). It covers amplitude, wavelength, frequency and period; the wave equation; transverse and longitudinal waves; modelling waves with ripples and sound; electromagnetic waves as transverse, and energy transfer; frequency and wavelength across the spectrum; what our eyes detect, and light as an electromagnetic wave; uses of electromagnetic waves; hazards of ultraviolet, X-rays and gamma rays; producing and receiving radio waves; absorption, transmission, refraction and reflection; and investigating reflection and refraction of light.
Where it is assessed
Paper 12 (Physics)
Combined Science A, Paper 12 (Physics): 1 hour 10 minutes, 60 marks, 16.7% of the qualification.
Check the OCR specification ↗The 12 subtopics
Each one has its own page.
- Amplitude, wavelength, frequency and periodAmplitude, period, wavelength and frequency and their units, the link between period and frequency with calculations, how amplitude relates to energy, how a point in a material moves as a wave passes, and measuring the wavelength of a longitudinal wave.Open →
- The wave equationWave velocity = frequency × wavelength and its units, why a higher frequency means a shorter wavelength at a fixed speed, pitch and wavelength in air, finding velocity from distance and time, and calculations of velocity, frequency and wavelength for sound, water and radio waves.Open →
- Transverse and longitudinal wavesHow the direction of vibration differs in transverse and longitudinal waves, crests and troughs, compressions and rarefactions, an example of each type, and what the two types have in common.Open →
- Modelling waves with ripples and soundWhy ripples model transverse waves and sound longitudinal ones, methods for measuring the speed of ripples and of sound, and the evidence that waves transfer energy without moving matter along.Open →
- Electromagnetic waves as transverse, and energy transferElectromagnetic waves as transverse waves that cross empty space at about 3 × 10⁸ m/s, why we can see the Sun but not hear it, and how infrared, microwaves, light, radio waves and ultraviolet transfer energy from a source to an absorber, including why a black car heats up faster.Open →
- Frequency and wavelength across the spectrumHow frequency and wavelength are related for electromagnetic waves, calculations using their common speed, the order of the spectrum, and which colours lie at each end of visible light.Open →
- What our eyes detect, and light as an electromagnetic waveThe narrow band of visible light the eye detects and the red and violet at its edges, why infrared and ultraviolet cannot be seen and how a thermal camera reveals infrared, and light as a transverse electromagnetic wave with the same speed as microwaves and a colour set by its wavelength.Open →
- Uses of electromagnetic wavesPractical uses of radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays, and why microwaves suit satellite links and light suits optical fibres.Open →
- Hazards of ultraviolet, X-rays and gamma raysEffects of too much ultraviolet on skin and how X-rays and gamma rays can harm the body.Open →
- Producing and receiving radio wavesHow oscillating charges in a circuit and aerial produce radio waves, how an arriving wave induces an alternating current of the same frequency, tuning a receiver to one station, the energy transferred on reception, and why radio waves need no material between transmitter and receiver.Open →
- Absorption, transmission, refraction and reflectionThe four things that can happen when a wave meets a substance, examples of absorption varying with wavelength from greenhouses to X-rays, and how and why light refracts entering or leaving glass.Open →
- Investigating reflection and refraction of lightInvestigating reflection by a plane mirror and refraction through a rectangular glass block with a ray box, why a narrow ray and widely spaced crosses give better angles, working safely in a darkened room, the independent and dependent variables, and the spectrum a prism produces.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
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Give the units of wave velocity, frequency and wavelength, and explain why, of two notes in the same air, the lower has the longer wavelength.
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Compare the vibrations in transverse and longitudinal waves, name the high and low points of a transverse wave, and define a compression.
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Why do ripples model a transverse wave and sound, forming compressions and rarefactions, a longitudinal one, and how can the speed of ripples be timed?
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Roughly how does the speed of sound in air compare with the speed of ripples on water?
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What is meant by the amplitude of a wave?
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Which has the higher frequency, a radio wave or an X-ray?
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Which part of the electromagnetic spectrum can the human eye detect?
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Which type of electromagnetic wave is used to communicate with satellites, and why is it suitable?
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Which three groupings of the electromagnetic spectrum are ionising?
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What happens in an aerial when a radio wave arrives at it?
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Give an example of a substance that transmits one part of the electromagnetic spectrum but absorbs another.
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What is meant by the period of a wave?
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State in words the relationship between wave velocity, frequency and wavelength.
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In a transverse wave, how does the direction of vibration compare with the direction the wave travels?
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Explain why we can see the Sun but cannot hear it.
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Which has the longer wavelength, infrared or ultraviolet?
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Roughly how much of the whole electromagnetic spectrum can we see?
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Which type of electromagnetic wave carries telephone and internet signals along optical fibres?
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Which of infrared and ultraviolet is ionising, and what does the other one do instead?
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Describe the energy transfer that takes place when a radio signal is received.
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Explain why a mobile phone signal weakens inside a building with thick stone walls.
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How is the period of a wave related to its frequency?
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What are the units of wave velocity, frequency and wavelength?
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In a longitudinal wave, how does the direction of vibration compare with the direction the wave travels?
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Explain why ripples on water are used as a model of a transverse wave.
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In an electromagnetic wave, in what direction are the oscillations?
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Why is it enough to know the frequency of an electromagnetic wave in order to work out its wavelength?
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How can infrared radiation be detected if the eye cannot see it?
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What has to change in a transmitting circuit to produce radio waves of a higher frequency?
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Explain why X-rays pass through soft tissue although visible light does not.
Process
In an investigation of refraction through a glass block, which is the independent variable and which is the dependent variable?
Process
Why are ray-tracing experiments carried out in a darkened room?
Process
Give a safety precaution when using a ray box.
Take Waves in Matter further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Transverse wave vs Longitudinal wave
Transverse wave: vibrations at right angles to the direction of travel. Longitudinal wave: vibrations along the same line as the direction of travel.
Frequency vs Period
Frequency: number of complete waves passing a point each second. Period: time taken for one complete wave to pass a fixed point.
Compression vs Rarefaction
Compression: region where particles are pushed closer together, at higher pressure. Rarefaction: region where particles are spread further apart, at lower pressure.
Questions from this topic
Each one with the model answer underneath.
- 1
What is meant by the amplitude of a wave?
Model answer
The maximum displacement of a point on the wave from its undisturbed rest position.
- 2
What is meant by the period of a wave?
Model answer
The time taken for one complete wave to pass a fixed point.
- 3
How is the period of a wave related to its frequency?
Model answer
The period is one divided by the frequency, so the two are reciprocals of each other.
- 4
A wave completes one full oscillation every 0.02 s. What is its frequency?
Model answer
Its frequency is 50 Hz, because 1 ÷ 0.02 = 50.
- 5
A wave has a frequency of 200 Hz. What is its period?
Model answer
Its period is 0.005 s, because 1 ÷ 200 = 0.005.
- 6
How does the amplitude of a wave relate to the energy it transfers?
Model answer
A wave of larger amplitude transfers more energy.
What is inside Levo
Six ways to work the same material.
Waves in Matter revision questions
- What does Waves in Matter cover in OCR GCSE Combined Science Physics?
- 12 subtopics: amplitude, wavelength, frequency and period, the wave equation, transverse and longitudinal waves, modelling waves with ripples and sound, electromagnetic waves as transverse, and energy transfer, frequency and wavelength across the spectrum, what our eyes detect, and light as an electromagnetic wave, uses of electromagnetic waves, hazards of ultraviolet, x-rays and gamma rays, producing and receiving radio waves, absorption, transmission, refraction and reflection and investigating reflection and refraction of light. Each one has its own page with questions and model answers.
- How is Waves in Matter organised?
- By the OCR J250 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Waves in Matter, 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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