Waves in Matter | OCR GCSE Physics A, Foundation tier (J249)
Waves in Matter
- 172 questions
- 12 subtopics
- Paper 2
- Paper 2
Waves in Matter is examined in Physics A Paper 2.
It covers amplitude, wavelength, frequency and period, the wave equation, transverse and longitudinal waves, sound crossing a boundary; reflection, transmission and absorption, 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, ray diagrams for reflection and refraction and how colour arises.
Sample questions from Waves in Matter
Answer each one closed book first, then open the answer.
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Amplitude, wavelength, frequency and period
How does the amplitude of a wave relate to the energy it transfers?
Show the answer
A wave of larger amplitude transfers more energy. -
The wave equation
Water waves travel at 0.2 m/s with a frequency of 4 Hz. What is their wavelength?
Show the answer
The wavelength is 0.05 m, because 0.2 ÷ 4 = 0.05. -
Sound crossing a boundary; reflection, transmission and absorption
In which state of matter does sound normally travel fastest?
Show the answer
In solids, because the particles are closest together and pass the vibration on most quickly. -
Modelling waves with ripples and sound
If air really did travel with a sound wave, what would you notice when someone spoke to you across a room?
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You would feel a steady stream of air arriving from the speaker. -
Frequency and wavelength across the spectrum
An infrared wave has a wavelength of 10 μm, which is 1 × 10⁻⁵ m. What is its frequency?
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Its frequency is 3 × 10¹³ Hz, because 3 × 10⁸ ÷ 1 × 10⁻⁵ = 3 × 10¹³. -
What our eyes detect, and light as an electromagnetic wave
How does the speed of light compare with the speed of microwaves in empty space?
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They are the same, because light is itself an electromagnetic wave. -
Hazards of ultraviolet, X-rays and gamma rays
Describe the effects of too much ultraviolet on skin.
Show the answer
It causes sunburn, ages the skin early and raises the risk of skin cancer. -
Ray diagrams for reflection and refraction
Describe how to investigate the refraction of light through a rectangular glass block.
Show the answer
Draw round the block on paper, shine a narrow ray from a ray box into one side at an angle and mark the entering and emerging rays with crosses, then remove the block, join the points to draw the ray through it, draw the normals and measure the angles of incidence and refraction with a protractor.
The 12 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Amplitude, wavelength, frequency and period | Amplitude, 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. | 16 |
| The wave equation | Wave 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. | 16 |
| Transverse and longitudinal waves | How 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. | 9 |
| Sound crossing a boundary; reflection, transmission and absorption | Which property of sound stays the same across a boundary, why wavelength changes, wavelength calculations in air and water, what reflection, transmission and absorption mean, and ultrasound and sonar uses. | 16 |
| Modelling waves with ripples and sound | Why 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. | 16 |
| Electromagnetic waves as transverse, and energy transfer | Electromagnetic 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. | 16 |
| Frequency and wavelength across the spectrum | How 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. | 16 |
| What our eyes detect, and light as an electromagnetic wave | The 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. | 16 |
| Uses of electromagnetic waves | Practical 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. | 9 |
| Hazards of ultraviolet, X-rays and gamma rays | Effects of too much ultraviolet on skin and how X-rays and gamma rays can harm the body. | 9 |
| Ray diagrams for reflection and refraction | How convex and concave lenses refract parallel rays, focal length, lenses for long and short sight, the law of reflection and the normal, the path of a ray through a glass block, and investigating reflection and refraction with a ray box, including the spectrum from a prism. | 24 |
| How colour arises | Why a red jumper looks red in white light, why an object looks white and why an object looks black. | 9 |
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 GCSE Physics A, Foundation tier Active Recall Guide
Every topic, not just this one. 1,303 questions with their answers.