Waves in Matter | OCR GCSE Physics A, Higher tier (J249)

Waves in Matter

220 questions
15 subtopics
Paper 4
Paper 4

Waves in Matter is examined in Physics A Paper 4.

It covers amplitude, wavelength, frequency and period, the wave equation, transverse and longitudinal waves, sound crossing a boundary; reflection, transmission and absorption, converting sound to vibrations, and the range of hearing, 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, exploring structures with waves, and producing radio waves, absorption, transmission, refraction and reflection, 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.

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.
Converting sound to vibrations, and the range of hearing

What name is given to sound above the range of human hearing?

Show the answer
Ultrasound.
Electromagnetic waves as transverse, and energy transfer

In an electromagnetic wave, in what direction are the oscillations?

Show the answer
At right angles to the direction in which the wave is travelling.
Frequency and wavelength across the spectrum

Which grouping lies between microwaves and visible light?

Show the answer
Infrared.
Uses of electromagnetic waves

Give a practical use of visible light other than seeing.

Show the answer
It is used to carry signals along optical fibres and to take photographs.
Hazards of ultraviolet, X-rays and gamma rays

How does someone who takes X-ray images at work reduce the risk to themselves?

Show the answer
They stand behind a lead screen, wear a badge that records their dose and keep each exposure as short as possible.

The 15 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
Converting sound to vibrations, and the range of hearing	How the outer ear, eardrum, middle ear bones and cochlea turn sound into nerve signals, how microphones and loudspeakers convert between sound and electrical signals, the 20 Hz to 20000 Hz range of human hearing, ultrasound, and why hearing is lost with age and loud noise.	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
Exploring structures with waves, and producing radio waves	How differences in absorption, reflection and speed let waves explore hidden structures, imaging the body with X-rays, ultrasound, infrared and gamma rays, why ultrasound suits an unborn baby but not the brain, and how radio waves are produced and received by oscillating charges in aerials and tuned circuits.	16
Absorption, transmission, refraction and reflection	The 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.	16
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

Waves in Matter is 220 of the 1,584 questions in the guide.Get the guide, £7

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.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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.
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.