10 free IGCSE Physics Waves questions written in the style of Cambridge Physics papers: 3 multiple-choice and 7 structured, each with its answer and mark scheme. 4 of them are A* challenge questions, built to catch the mistakes strong students still make.
This topic covers General properties of waves, Reflection & refraction, Thin lenses, Electromagnetic spectrum, Sound. Work through the questions below, then generate a full Waves paper with a fresh set every time.
Generate a full Waves paper →An object is placed closer to a thin converging lens than its principal focus.
Which row describes the image?
| nature | orientation | size compared with object | |
|---|---|---|---|
| A | virtual | upright | smaller |
| B | virtual | upright | larger |
| C | virtual | inverted | larger |
| D | real | inverted | larger |
Answer: B
A wave has a frequency of 8 Hz and a wavelength of 0.06 m. What is the speed of the wave?
Answer: B
Which part of the electromagnetic spectrum has the shortest wavelength?
Answer: A
A ship uses pulses of ultrasound of frequency 50 kHz to measure the depth of the sea. The speed of sound in sea water is 1500 m/s.
State what is meant by ultrasound.
Calculate the wavelength of the ultrasound in sea water.
An echo from the sea bed is received 0.32 s after a pulse is sent. Calculate the depth of the sea.
Pulses are sent every 0.50 s. Explain why the ship cannot measure the depth correctly where the sea is deeper than 375 m.
State one reason why ultrasound rather than audible sound is used.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | sound with a frequency above 20 kHz (above the upper limit of human hearing) frequency above 20 kHz / above the range of human hearing B1 | 1 |
| (b) | 0.03 m λ = v ÷ f with f in Hz C1 0.03 A1 | 2 |
| (c) | 240 m distance = speed × time, halved for the return journey C1 240 A1 | 2 |
| (d) | Echoes from deeper than 375 m take longer than 0.50 s to return, so they arrive after the next pulse has been sent and cannot be matched to the correct pulse echo time > 0.50 s (2 × 375 ÷ 1500) B1 the echo arrives after the next pulse is sent, so it is matched to the wrong pulse B1 | 2 |
| (e) | Short wavelength gives more detail / can be directed in a narrow beam / does not disturb people short wavelength, so more detail / narrow beam / inaudible B1 | 1 |
Fig. 5.1 shows water waves in a ripple tank at one instant. 12 wavefronts pass a fixed point in 2.0 s.
Determine the amplitude and the wavelength of the waves.
Calculate the frequency and the speed of the waves. Give the speed in m/s.
The waves pass into a shallower region where they travel more slowly. The frequency does not change. State and explain what happens to the wavelength.
The waves then pass through a gap equal in width to their wavelength. Describe the waves after the gap, and state how this would change if the gap were much wider.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | 1.5 cm, 4 cm 1.5 cm B1 4 cm B1 | 2 |
| (b) | 6 Hz, 0.24 m/s f = 12 ÷ 2 = 6 Hz B1 v = fλ C1 0.24 m/s (λ in m) A1 | 3 |
| (c) | Wavelength decreases: v = fλ with f constant, so λ is proportional to v wavelength decreases B1 f unchanged so λ ∝ v (v = fλ) B1 | 2 |
| (d) | They spread out (diffract) into semicircular wavefronts with the same wavelength; with a much wider gap there is much less spreading diffraction: waves spread out (curved wavefronts), wavelength unchanged B1 wider gap gives less diffraction / spreading B1 | 2 |
An object is placed 30 cm from a converging lens of focal length 10 cm.
On a ray diagram, describe the two rays you would draw to locate the image.
State three properties of the image.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | parallel ray through focus; ray through centre undeviated a ray parallel to the axis refracts through the principal focus B1 a ray through the centre of the lens goes straight on B1 | 2 |
| (b) | real, inverted, diminished real B1 inverted B1 diminished (smaller than the object) B1 | 3 |
The electromagnetic spectrum includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays.
State two properties shared by all electromagnetic waves.
State one use of microwaves and one use of X-rays.
State one harmful effect of ultraviolet radiation.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | transverse; same speed in vacuum Any 2 of: transverse; travel at the same speed in a vacuum (3.0 × 10⁸ m/s); can travel through a vacuum B2 | 2 |
| (b) | cooking/communication; medical imaging microwaves: cooking / mobile phones / satellite communication B1 X-rays: medical imaging / airport security B1 | 2 |
| (c) | skin cancer / eye damage damage to surface cells / skin cancer / eye damage B1 | 1 |
A plane mirror forms an image of an object.
State the law of reflection.
State three properties of the image formed by a plane mirror.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | angle of incidence = angle of reflection angle of incidence = angle of reflection B1 | 1 |
| (b) | virtual, upright, same size, same distance behind Any 3 of: virtual; upright; same size; same distance behind the mirror as the object; laterally inverted B3 | 3 |
Waves can be transverse or longitudinal.
Describe the difference between a transverse and a longitudinal wave.
Give one example of each.
State what is transferred by a wave.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | direction of vibration relative to travel transverse: vibrations perpendicular to the direction of energy travel B1 longitudinal: vibrations parallel to the direction of travel B1 | 2 |
| (b) | light; sound transverse: light / any electromagnetic wave / water waves B1 longitudinal: sound / ultrasound B1 | 2 |
| (c) | energy energy (not matter) B1 | 1 |
This question is about sound.
Describe how sound travels through air.
A student stands 85 m from a wall and claps. She hears the echo 0.500 s later. Calculate the speed of sound.
State the range of frequencies audible to a healthy human ear.
A ship sends a pulse of ultrasound to the sea bed. The echo returns after 0.800 s. The speed of sound in sea water is 1500 m/s. Calculate the depth of the sea.
Explain why sound travels faster in water than in air.
A note becomes louder and higher in pitch. State how the amplitude and the frequency of the sound wave change.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | longitudinal wave; compressions and rarefactions longitudinal wave / vibrations of air particles parallel to direction of travel B1 series of compressions and rarefactions B1 | 2 |
| (b) | 340 m/s distance travelled = 170 m C1 170/0.500 = 340 m/s A1 | 2 |
| (c) | 20 Hz to 20 000 Hz 20 Hz to 20 kHz B1 | 1 |
| (d) | 600 m distance = 1500 × 0.800 = 1200 m C1 depth = 600 m A1 | 2 |
| (e) | particles closer together, vibrations passed on more quickly particles are closer together so vibrations are passed on more quickly B1 | 1 |
| (f) | amplitude increases; frequency increases amplitude increases (louder) B1 frequency increases (higher pitch) B1 | 2 |
In the 0625 syllabus, Waves covers General properties of waves, Reflection & refraction, Thin lenses, Electromagnetic spectrum, Sound.
This page has 10 Waves questions with answers. For more, the free generator on mentorriyaz.in builds a new Waves paper with a full mark scheme each time you click.
Riyaz Shaikh has mentored IGCSE, IB and A Level students for 15+ years, one-on-one, online and in Mumbai. The hardest questions on this site are the ones he uses to find a student's weak points.
Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in