Waves
50 exam-style questions with answers for 4.6 Waves in AQA GCSE Physics (spec 8463). Practise with flashcards, a topic quiz, a random quiz across the course, 5 crosswords, or read every question and answer below. Not official AQA material.
All 50 questions and answers
Question 1 · Spec 4.6.1.1 · Wave types
What is the difference between transverse and longitudinal waves? [2 marks]
Answer:In transverse waves, the oscillations are perpendicular to the direction of energy transfer (1); in longitudinal waves, they are parallel to it (1).Question 2 · Spec 4.6.1.1 · Wave types
Give one example of a transverse wave and one of a longitudinal wave. [2 marks]
Answer:Transverse: ripples on water or light (1); longitudinal: sound waves (1).Question 3 · Spec 4.6.1.1 · Wave types
What evidence shows that it is the wave, not the water, that moves? [1 mark]
Answer:A floating object bobs up and down but does not travel along with the ripples.Question 4 · Spec 4.6.1.1 · Longitudinal
What are compressions and rarefactions? [2 marks]
Answer:Compressions are regions where the particles are close together (1); rarefactions are regions where they are spread apart (1).Question 5 · Spec 4.6.1.2 · Wave properties
Define amplitude. [1 mark]
Answer:The maximum displacement of a point on a wave from its undisturbed position.Question 6 · Spec 4.6.1.2 · Wave properties
Define wavelength. [1 mark]
Answer:The distance from a point on one wave to the equivalent point on the next wave.Question 7 · Spec 4.6.1.2 · Wave properties
Define frequency. [1 mark]
Answer:The number of waves passing a point each second, measured in hertz (Hz).Question 8 · Spec 4.6.1.2 · Period
A wave has a frequency of 50 Hz. Calculate its period. [2 marks]
Answer:T = 1 ÷ f = 1 ÷ 50 (1); = 0.02 s (1).Question 9 · Spec 4.6.1.2 · Wave equation
State the wave equation. [1 mark]
Answer:Wave speed = frequency × wavelength (v = fλ).Question 10 · Spec 4.6.1.2 · Wave equation
A wave has a frequency of 400 Hz and a wavelength of 0.85 m. Calculate its speed. [2 marks]
Answer:v = fλ = 400 × 0.85 (1); = 340 m/s (1).Question 11 · Spec 4.6.1.2 · Speed of sound
Describe how to measure the speed of sound in air. [2 marks]
Answer:Measure the distance between two people and time how long a loud sound takes to travel between them (1); speed = distance ÷ time (1).Question 12 · Spec 4.6.1.2 · Required practical 8
Describe how to measure the speed of water waves in a ripple tank. [2 marks]
Answer:Use a strobe or count waves passing a point in 10 s to find the frequency, and measure the wavelength with a ruler (1); calculate v = fλ (1).Question 13 · Spec 4.6.1.2 · Required practical 8
How do you measure the wavelength of waves on a string? [1 mark]
Answer:Measure the length of several half wavelengths (loops) and use it to calculate one wavelength.Question 14 · Spec 4.6.1.3 · Reflection
What can happen to waves at a boundary between two materials? [3 marks]
Answer:They can be reflected (1); absorbed (1); or transmitted (1).Question 15 · Spec 4.6.1.3 · Reflection
What is specular reflection? [1 mark]
Answer:Reflection from a smooth surface in a single direction.Question 16 · Spec 4.6.1.4 · Sound · Higher only
How does the ear detect sound? [2 marks]
Answer:Sound waves make the eardrum vibrate (1); these vibrations are passed through the ear to the cochlea and converted to signals (1).Question 17 · Spec 4.6.1.4 · Sound · Higher only
What is the range of normal human hearing? [1 mark]
Answer:20 Hz to 20 kHz.Question 18 · Spec 4.6.1.5 · Ultrasound · Higher only
What is ultrasound? [1 mark]
Answer:Sound with a frequency higher than 20 kHz, above the range of human hearing.Question 19 · Spec 4.6.1.5 · Ultrasound · Higher only
How does ultrasound produce an image of a fetus? [2 marks]
Answer:Ultrasound is partly reflected at boundaries between different tissues (1); the time for reflections to return is used to find the distance to each boundary (1).Question 20 · Spec 4.6.1.5 · Seismic waves · Higher only
Explain how S-waves gave evidence for the Earth's liquid outer core. [2 marks]
Answer:S-waves are transverse and cannot travel through liquids (1); they are not detected on the opposite side of the Earth, forming a shadow zone (1).Question 21 · Spec 4.6.1.5 · Echo sounding · Higher only
How is echo sounding used to measure sea depth? [2 marks]
Answer:A pulse of high-frequency sound is sent to the sea bed and the time for the echo is measured (1); depth = speed × time ÷ 2 (1).Question 22 · Spec 4.6.2.1 · EM spectrum
List the electromagnetic spectrum from longest wavelength. [2 marks]
Answer:Radio, microwaves, infrared, visible light (1); ultraviolet, X-rays, gamma rays (1).Question 23 · Spec 4.6.2.1 · EM spectrum
State two properties shared by all electromagnetic waves. [2 marks]
Answer:Any two from: they are transverse (1); they travel at the same speed in a vacuum (1); they transfer energy from source to absorber (1).Question 24 · Spec 4.6.2.2 · Refraction
What is refraction? [1 mark]
Answer:The change in direction of a wave when it passes from one medium into another at an angle.Question 25 · Spec 4.6.2.2 · Refraction · Higher only
Explain why light refracts towards the normal when entering glass. [2 marks]
Answer:Light slows down in glass (1); so the part of the wave front that enters first slows first, changing the direction (1).Question 26 · Spec 4.6.2.2 · Required practical 10
Describe how to compare infrared emitted by different surfaces. [2 marks]
Answer:Fill a Leslie cube with hot water and measure the infrared emitted from each face with an infrared detector at the same distance (1); matt black emits most, shiny silver least (1).Question 27 · Spec 4.6.2.3 · Radio waves · Higher only
How are radio waves produced and absorbed? [2 marks]
Answer:They are produced by oscillations in electrical circuits (1); when absorbed, they can create an alternating current with the same frequency (1).Question 28 · Spec 4.6.2.3 · Dangers
State two hazards of ultraviolet radiation. [2 marks]
Answer:Premature skin ageing (1); increased risk of skin cancer (1).Question 29 · Spec 4.6.2.3 · Dangers
Why are X-rays and gamma rays dangerous? [1 mark]
Answer:They are ionising radiation that can cause mutations of genes and cancer.Question 30 · Spec 4.6.2.4 · Uses
State one use each of radio waves, microwaves and infrared. [3 marks]
Answer:Radio: television and radio broadcasting (1); microwaves: satellite communications or cooking (1); infrared: electrical heaters, cooking or infrared cameras (1).Question 31 · Spec 4.6.2.4 · Uses
State one use each of visible light, ultraviolet and X-rays. [3 marks]
Answer:Visible: fibre optic communications (1); ultraviolet: energy-efficient lamps or sun tanning (1); X-rays: medical imaging (1).Question 32 · Spec 4.6.2.4 · Uses · Higher only
Why are microwaves used for satellite communication? [1 mark]
Answer:They can pass through the atmosphere to reach satellites.Question 33 · Spec 4.6.2.5 · Lenses
What does a convex lens do to parallel rays of light? [1 mark]
Answer:It brings them together at the principal focus.Question 34 · Spec 4.6.2.5 · Lenses
State the equation for magnification. [1 mark]
Answer:Magnification = image height ÷ object height.Question 35 · Spec 4.6.2.5 · Lenses
An object 2 cm tall forms an image 7 cm tall. Calculate the magnification. [1 mark]
Answer:7 ÷ 2 = 3.5 (no units).Question 36 · Spec 4.6.2.5 · Lenses
What type of image does a concave lens produce? [1 mark]
Answer:A virtual image.Question 37 · Spec 4.6.2.6 · Visible light
Why does a red object look red in white light? [2 marks]
Answer:It reflects red wavelengths (1); and absorbs all the other colours (1).Question 38 · Spec 4.6.2.6 · Visible light
What colour does a green object appear through a red filter? [1 mark]
Answer:Black, because the filter only lets red light through and the green object reflects no red.Question 39 · Spec 4.6.2.6 · Visible light
What is diffuse reflection? [1 mark]
Answer:Reflection from a rough surface that scatters light in many directions.Question 40 · Spec 4.6.3.1 · Infrared
What does the intensity and wavelength of radiation emitted by an object depend on? [1 mark]
Answer:Its temperature.Question 41 · Spec 4.6.3.2 · Black bodies
What is a perfect black body? [2 marks]
Answer:An object that absorbs all the radiation incident on it (1); it is also the best possible emitter (1).Question 42 · Spec 4.6.3.2 · Constant temperature · Higher only
Why does an object stay at a constant temperature? [1 mark]
Answer:It absorbs radiation at the same rate as it emits radiation.Question 43 · Spec 4.6.3.2 · Earth's temperature · Higher only
State two factors that affect the temperature of the Earth. [2 marks]
Answer:Any two from: the rates of absorption and emission of radiation (1); reflection of radiation into space by clouds and ice (1); greenhouse gases in the atmosphere (1).Question 44 · Spec 4.6.1.2 · Wave equation
A radio wave has a frequency of 100 MHz and travels at 3 × 10⁸ m/s. Calculate its wavelength. [2 marks]
Answer:λ = v ÷ f = 3 × 10⁸ ÷ 1 × 10⁸ (1); = 3 m (1).Question 45 · Spec 4.6.2.1 · EM spectrum
Which part of the EM spectrum can the human eye detect? [1 mark]
Answer:Visible light only.Question 46 · Spec 4.6.2.4 · Uses
Why are X-rays used to see broken bones? [1 mark]
Answer:They pass through soft tissue but are absorbed by bone.Question 47 · Spec 4.6.1.2 · Wave properties
What happens to wavelength if frequency doubles at constant wave speed? [1 mark]
Answer:It halves.Question 48 · Spec 4.6.2.5 · Lenses
What is the focal length of a lens? [1 mark]
Answer:The distance from the lens to the principal focus.Question 49 · Spec 4.6.2.2 · Refraction
What happens to a light ray entering a glass block along the normal? [1 mark]
Answer:It does not change direction (but it slows down).Question 50 · Spec 4.6.1.5 · Ultrasound · Higher only
An ultrasound echo returns from a boundary after 0.0002 s. Speed in tissue = 1500 m/s. How deep is the boundary? [2 marks]
Answer:Distance there and back = 1500 × 0.0002 = 0.3 m (1); depth = 0.3 ÷ 2 = 0.15 m (1).