3.1

General properties of waves

Cambridge IGCSE Physics (0625)  · Unit 3: Waves  · 18 flashcards

General properties of waves is topic 3.1 in the Cambridge IGCSE Physics (0625) syllabus , positioned in Unit 3 — Waves , alongside Reflection of light, Refraction of light and Thin lenses.  In one line: Waves transfer energy. Waves do *not* transfer matter.

This topic is examined in Paper 1 (multiple-choice) and Papers 3/4 (theory), plus Paper 5 or Paper 6 (practical / alternative to practical). Past papers from 2022 to 2025 show this topic across undefined questions worth 249 marks (around 3.9% of all Physics marks in those years).

The deck below contains 18 flashcards — 1 definition — covering the precise wording mark schemes reward.  Use the definition card to lock down command-word answers (define, state), then move on to the concept and application cards to handle explain, describe and compare questions.

Key definition

State what is transferred by all types of waves, and what is *not* transferred

Waves transfer energy. Waves do *not* transfer matter.

What the Cambridge 0625 syllabus says

Official 2026-2028 spec

These are the exact learning objectives Cambridge sets for this topic. Match the command word (Describe, Explain, State, etc.) in your answer to score full marks.

  1. Know Know that waves transfer energy without transferring matter
  2. Describe Describe what is meant by wave motion as illustrated by vibrations in ropes and springs, and by experiments using water waves
  3. Describe Describe the features of a wave in terms of wavefront, wavelength, frequency, crest (peak), trough, amplitude and wave speed
  4. Recall Recall and use the equation for wave speed v = fλ
  5. Know Know that for a transverse wave, the direction of vibration is at right angles to the direction of propagation and understand that electromagnetic radiation, water waves and seismic S-waves (secondary) can be modelled as transverse
  6. Know Know that for a longitudinal wave, the direction of vibration is parallel to the direction of propagation and understand that sound waves and seismic P-waves (primary) can be modelled as longitudinal
  7. Describe Describe how waves can undergo: (a) reflection at a plane surface (b) refraction due to a change of speed (c) diffraction through a narrow gap
  8. Describe Describe the use of a ripple tank to show: (a) reflection at a plane surface (b) refraction due to a change in speed caused by a change in depth (c) diffraction due to a gap (d) diffraction due to an edge
  9. Describe Describe how wavelength and gap size affects diffraction through a gap Supplement
  10. Describe Describe how wavelength affects diffraction at an edge Supplement
Definition Flip

State what is transferred by all types of waves, and what is *not* transferred.

Answer Flip

Waves transfer energy. Waves do *not* transfer matter.

Key Concept Flip

A student shakes one end of a long rope. They observe a wave traveling down the rope. Explain why this demonstrates that waves transfer energy but not matter.

Answer Flip

The wave travels down the rope carrying energy from the student's hand. The particles of the rope vibrate (move up and down or side to side) but do not travel along the rope with the wave. Thus, energy is transferred, but matter is not.

Key Concept Flip

A student vibrates one end of a long spring back and forth with a frequency of 2.0 Hz. This creates a wave that travels down the spring at a speed of 4.0 m/s. Calculate the wavelength of the wave produced.

Answer Flip

Formula: wave speed (v) = frequency (f) x wavelength (λ)
Rearrange to find wavelength: λ = v / f
λ = 4.0 m/s / 2.0 Hz
λ = 2.0 m

Answer: The wavelength of the wave is 2.0 meters. Wave speed is the product of frequency and wavelength, therefore dividing speed by frequency gives wavelength.

Key Concept Flip

Describe how the movement of a single point on a rope demonstrates wave motion when a wave travels along the rope. Assume the wave is moving horizontally from left to right.

Answer Flip

As the wave passes, a point on the rope oscillates (moves up and down/vibrates) vertically. It does *not* travel horizontally with the wave. The point returns to its original position after the wave has passed. The energy of the wave is what travels horizontally, not the particles of the medium.

Key Concept Flip

A wave has a frequency of 2.0 Hz and a wavelength of 1.3 m. Calculate the speed of the wave.

Answer Flip

Wave speed (v) = frequency (f) x wavelength (λ)
v = 2.0 Hz x 1.3 m
v = 2.6 m/s

The wave speed is calculated by multiplying the frequency and wavelength.

Key Concept Flip

Describe the difference between the crest and trough of a wave.

Answer Flip

The crest is the highest point of the wave above the equilibrium position, while the trough is the lowest point of the wave below the equilibrium position. They represent the points of maximum positive and negative displacement, respectively.

Key Concept Flip

A wave has a frequency of 5 Hz and a wavelength of 1.2 m. Calculate the speed of the wave.

Answer Flip

v = fλ
v = 5 Hz * 1.2 m
v = 6.0 m/s

The speed of the wave is calculated by multiplying its frequency (number of waves per second) by its wavelength (the length of one complete wave).

Key Concept Flip

A water wave travels at 2.0 m/s and has a wavelength of 0.4 m. Determine the frequency of the wave.

Answer Flip

v = fλ => f = v/λ
f = 2.0 m/s / 0.4 m
f = 5.0 Hz

The frequency is calculated by rearranging the wave speed equation and dividing the wave speed by its wavelength.

Key Concept Flip

A water wave travels across a lake. A small cork on the surface of the water bobs up and down. If the wave travels 4.0 meters in 2 seconds and the cork bobs up and down 3 times in those 2 seconds, calculate the wavelength of the water wave.

Answer Flip

Formula: wave speed (v) = frequency (f) x wavelength (λ)
1. Calculate frequency: f = number of oscillations / time = 3 / 2 = 1.5 Hz
2. Calculate wave speed: v = distance / time = 4.0 m / 2 s = 2.0 m/s
3. Rearrange formula: λ = v / f
4. Substitute values: λ = 2.0 m/s / 1.5 Hz = 1.33 m
Answer: The wavelength of the water wave is 1.33 m. This calculation relies on understanding that water waves are transverse and the frequency relates to how often the cork moves up/down.

Key Concept Flip

State three examples of waves that can be modelled as transverse waves.

Answer Flip

1. Electromagnetic radiation (e.g. light, radio waves)
2. Water waves
3. Seismic S-waves (secondary waves)
Explanation: Transverse waves have vibrations perpendicular to the direction of energy transfer. Each of these examples exhibits this property and therefore can be modelled as such.

Key Concept Flip

A seismic P-wave travels through the Earth at a speed of 8000 m/s. Two monitoring stations, A and B, are 40 km apart. If the P-wave is longitudinal, calculate the time difference between the arrival of the wave at station A and station B. Give your answer in seconds.

Answer Flip

Time = Distance / Speed
Distance = 40 km = 40000 m
Time = 40000 m / 8000 m/s = 5 s

Explanation: P-waves are longitudinal, meaning the vibration of the particles is parallel to the direction of wave propagation. This question tests your ability to relate speed, distance and time.

Key Concept Flip

State two features that are common to both sound waves in air and seismic P-waves in rock.

Answer Flip

1. Both are longitudinal waves, meaning the direction of vibration is parallel to the direction of propagation.
2. Both transfer energy through a medium via compressions and rarefactions. They both require a medium to travel through (cannot travel through a vacuum).

Explanation: This question tests your understanding of the fundamental properties of longitudinal waves.

Key Concept Flip

A water wave in a ripple tank travels from deep water to shallow water. The speed of the wave changes from 0.3 m/s to 0.2 m/s. Describe what happens to the wave as it enters the shallow water, considering both its speed and direction.

Answer Flip

As the water wave enters the shallow water, it refracts because the speed of the wave decreases from 0.3 m/s to 0.2 m/s. Refraction is the change in direction of a wave due to a change in speed. The wavelength also decreases, but the frequency remains constant.

Key Concept Flip

A wave approaches a barrier with a narrow gap. State two factors that affect the amount of diffraction of the wave as it passes through the gap.

Answer Flip

1. Wavelength of the wave: The longer the wavelength, the greater the diffraction. 2. Width of the gap: The narrower the gap (compared to the wavelength), the greater the diffraction.

Key Concept Flip

Describe how a ripple tank can be used to demonstrate the reflection of water waves at a plane surface. Include a diagram in your description.

Answer Flip

Diagram should show:
1. A ripple tank with a barrier placed at an angle.
2. Incident waves approaching the barrier.
3. Reflected waves leaving the barrier at an equal angle (angle of incidence equals angle of reflection).

Description should mention:
1. Waves generated by the dipper travel towards the barrier.
2. When the waves hit the barrier, they bounce back (are reflected).
3. The angle of incidence is equal to the angle of reflection.
This can be measured using a stroboscope to freeze the motion of the waves and a ruler to measure the angles.

Key Concept Flip

State two observations you would make in a ripple tank experiment that indicate refraction is occurring as water waves pass from a region of deep water to a region of shallow water.

Answer Flip

1. The wavelength of the waves decreases as they enter the shallow water.
2. The speed of the waves decreases as they enter the shallow water.

Explanation: Refraction occurs because the speed of the wave changes as it moves from deep to shallow water. Since frequency stays constant, a change in speed implies a change in wavelength.

Key Concept Flip

A water wave with a wavelength of 4.0 cm approaches a gap of width 2.0 cm. The wave then approaches a different gap of width 8.0 cm. Describe how the diffraction of the wave differs in each case.

Answer Flip

Smaller gap (2.0 cm): Significant diffraction occurs as the gap size is smaller than or approximately equal to the wavelength. The wavefronts will spread out significantly after passing through the gap.

Larger gap (8.0 cm): Less diffraction occurs because the gap size is significantly larger than the wavelength. The wavefronts will pass through the gap with less spreading.

Key Concept Flip

State two factors that influence the amount of diffraction that occurs when a wave passes through a gap.

Answer Flip

1. Wavelength of the wave.
2. Width of the gap.

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2.3.4 Consequences of thermal energy transfer 3.2.1 Reflection of light

Key Questions: General properties of waves

State what is transferred by all types of waves, and what is *not* transferred.

Waves transfer energy. Waves do *not* transfer matter.

Tips to avoid common mistakes in General properties of waves

More topics in Unit 3 — Waves

General properties of waves sits alongside these Physics decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.

Cambridge syllabus keywords to use in your answers

These are the official Cambridge 0625 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.

wave wavelength frequency amplitude period wave speed transverse longitudinal v=fλ crest trough compression rarefaction oscillation ripple tank wavefront

Key terms covered in this General properties of waves deck

Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.

What is transferred by all types of waves, and what is *not* transferred

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