OCR GCSE Physics A: Wave properties, transverse and longitudinal waves (J249) – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions cover statements P5.1a to P5.1e, P5.1j and P5.1k of OCR GCSE (9-1) Gateway Science Physics A (J249, Version 5.0, July 2026), topic P5.1 Wave behaviour. The specification does not print any of them in bold. Any question that needs the speed of sound gives it. Read the study guide or the revision notes first if needed. Course pages: the OCR GCSE Physics hub and the checklist. Not sure where to start? Try the free 10-minute diagnostics.

Questions

1. Define each of these terms for a wave.

(a) Wavelength [1] (b) Frequency [1] (c) Amplitude [1]

2. On a displacement-distance graph of a wave on a rope, the highest and lowest points are 9.0 cm apart vertically. Three complete waves occupy 1.5 m of rope.

(a) State the amplitude of the wave. [2] (b) Calculate the wavelength. [2]

3. A wave on a spring has frequency 15 Hz and wavelength 0.20 m.

(a) Calculate the speed of the wave. [3] (b) Calculate its period, to 2 significant figures. [2]

4. A loudspeaker emits a note of frequency 680 Hz. In air, sound travels at 340 m/s.

(a) Calculate the wavelength. [3] (b) A second note has wavelength 0.40 m in the same air. Calculate its frequency. [2]

5. Four waves are listed: ripples on a pond, sound from a speaker, a wave on a skipping rope, and a pulse made by pushing a slinky in and out along its length.

(a) State which two are transverse. [2] (b) Describe how the direction of vibration compares with the direction of travel in a transverse wave and in a longitudinal wave. [2]

6. Describe how you would use a slinky spring to model a transverse pulse and a longitudinal pulse, and what you would see in each case. [5]

7. Describe evidence that it is the wave that travels, and not the medium, for:

(a) ripples on water [3] (b) sound waves in air [3]

8. A pupil stands 68.0 m from a large wall and claps once. A digital timer records 0.40 s until the echo is heard.

(a) Calculate the speed of sound. [3] (b) The pupil repeats the experiment with a hand-held stopwatch and gets times between 0.30 s and 0.55 s. Explain why, and suggest one improvement. [2]

9. A ripple tank dipper is set to different frequencies. The wavelength is measured on the screen each time.

Frequency (Hz)	4.0	6.0	8.0
Wavelength (cm)	6.0	4.0	3.0

(a) Calculate the wave speed in m/s for the frequency of 4.0 Hz. [2] (b) Show that the data for 6.0 Hz gives the same speed. [2] (c) Predict the wavelength in cm at 12.0 Hz. [2] (d) State what happens to the wavelength as the frequency increases at constant speed. [1]

10. An oscilloscope shows a trace from a microphone. Nine complete waves occupy 18 ms.

(a) Calculate the period. [2] (b) Calculate the frequency. [1] (c) The sound travels at 340 m/s in air. Calculate the wavelength. [2]

11. A starter pistol is fired. An observer 400 m away starts a stopwatch on seeing the flash and stops it on hearing the bang, 1.17 s later.

(a) Explain why the time taken by light can be ignored. [1] (b) Calculate the speed of sound, to 3 significant figures. [2] (c) The bang contains a component of frequency 1.2 kHz. Calculate its wavelength using your answer to (b). [3] (d) Suggest two ways to make the result more reliable. [2]

12. A dipper in a ripple tank makes ripples at 9.0 Hz. A photograph with a ruler shows that 7 wavelengths cover 0.126 m.

(a) Explain why the length of 7 wavelengths is measured, not one. [1] (b) Calculate the wavelength. [2] (c) Calculate the speed of the ripples, to 2 significant figures. [2] (d) Explain why ripples are a suitable model for a transverse wave. [2] (e) State what is transferred from the dipper to the edge of the tank by the ripples. [1]

Answers

1. (a) The length of one complete wave, such as the gap between neighbouring crests [1] (b) The number of waves passing a point each second (or vibrations per second) [1] (c) The maximum displacement from the rest (middle) position [1] [3] Examiner insight: A definition needs the idea of per second for frequency and of the middle line for amplitude. Saying “how fast the wave goes” describes speed.

2. (a) Amplitude is measured from the middle line, so half the vertical gap [1]; 9.0 ÷ 2 = 4.5 cm [1] (b) 1.5 ÷ 3 [1] = 0.50 m [1] [4] Examiner insight: Giving 9.0 cm for the amplitude is the usual slip, because the full gap is crest to trough.

3. (a) v = f × λ [1]; = 15 × 0.20 [1] = 3.0 m/s [1] (b) T = 1 ÷ f = 1 ÷ 15 [1] = 0.067 s [1] [5] Examiner insight: Show the equation, the substitution and the answer with its unit, so that each step of your reasoning is visible.

4. (a) λ = v ÷ f [1]; = 340 ÷ 680 [1] = 0.50 m [1] (b) f = 340 ÷ 0.40 [1] = 850 Hz [1] [5] Examiner insight: Rearranging from v = f λ in the wrong direction (multiplying 340 by 680) is the most common way to lose these marks.

5. (a) Ripples on a pond [1]; wave on a skipping rope [1] (b) Transverse: the vibration is perpendicular to the way the wave moves [1]; longitudinal: the vibration is along the way the wave moves [1] [4] Examiner insight: Name both directions relative to the travel direction. Saying “up and down” alone does not describe the relationship.

6. Stretch the slinky along a bench or floor [1]. Transverse: move one end sideways, so a pulse travels along the spring while the coils move from side to side [1]. The coils move perpendicular to the way the pulse travels [1]. Longitudinal: push the end in and out along the spring, so bunched coils (compressions) and stretched coils (rarefactions) travel along it [1]. The coils move back and forth parallel to the travel direction [1] [5] Examiner insight: A full description states the action, what you see, and the direction of coil movement. Marks go to the observation, not just the setup.

7. (a) Float a cork (or small piece of polystyrene) on the water [1]. As ripples pass, it moves up and down about the same place [1]. It is not carried to the edge, so the water does not travel with the ripples; the wave does [1] (b) Sound is heard across a room with no steady wind from the source [1]. Smoke or light dust near a loudspeaker shakes to and fro about its position and does not drift away [1]. So the air vibrates about fixed positions and passes on the disturbance; the air is not carried to the listener [1] [6] Examiner insight: State the observation and then the conclusion. An answer that says only “the air does not move” gives no evidence.

8. (a) Distance travelled = 2 × 68.0 = 136 m [1]; v = 136 ÷ 0.40 [1] = 340 m/s [1] (b) Hand timing has reaction-time error that is large compared with 0.40 s [1]. Use a longer distance (a longer time), electronic timing, or repeat and average [1] [5] Examiner insight: Using 68.0 m as the distance is the typical error. The sound goes to the wall and back.

9. (a) λ = 6.0 cm = 0.060 m [1]; v = 4.0 × 0.060 = 0.24 m/s [1] (b) 4.0 cm = 0.040 m [1]; 6.0 × 0.040 = 0.24 m/s, the same [1] (c) λ = v ÷ f = 0.24 ÷ 12.0 [1] = 0.020 m = 2.0 cm [1] (d) The wavelength decreases (it halves when the frequency doubles) [1] [7] Examiner insight: Convert centimetres to metres before you use m/s. For “show that”, write both the working and the comparison.

10. (a) 18 ms ÷ 9 [1] = 2.0 ms (0.0020 s) [1] (b) f = 1 ÷ 0.0020 = 500 Hz [1] (c) λ = 340 ÷ 500 [1] = 0.68 m [1] [5] Examiner insight: Take the time for one wave from the whole trace. A single gap between peaks on a time axis is a period, not a wavelength.

11. (a) Light travels much faster than sound, so the time it takes over 400 m is negligible [1] (b) v = 400 ÷ 1.17 [1] = 342 m/s [1] (c) f = 1200 Hz [1]; λ = 342 ÷ 1200 [1] = 0.285 m [1] (d) Any two: repeat and find the mean; use a greater distance; use electronic timing; use several observers [2] [8] Examiner insight: Convert kHz to Hz first. Reliability points need a method (repeat and average), not just “be careful”.

12. (a) It reduces the percentage error from reading the ruler [1] (b) 0.126 ÷ 7 [1] = 0.018 m [1] (c) v = 9.0 × 0.018 [1] = 0.162, so 0.16 m/s [1] (d) The water surface moves up and down [1], at right angles to the direction the ripples travel [1] (e) Energy [1] [8] Examiner insight: Part (e) is lost by answering “water”. The water vibrates in place; energy is what travels.

Where marks are usually lost

• Giving the full crest-to-trough height as the amplitude.
• Leaving cm, mm, kHz or ms unconverted before using v = f λ.
• Rearranging the equation the wrong way round, so that speed is divided by frequency to give a speed.
• Reading a period from a displacement-distance graph or a wavelength from a displacement-time graph.
• Using the distance to the wall rather than twice that distance in echo methods.
• Describing transverse and longitudinal waves without comparing vibration with the direction of travel.
• Saying the water or air “moves with” the wave, instead of vibrating about fixed positions.
• Describing a speed measurement without stating what is measured, how, and what is calculated.

Next steps

• Go back over the revision notes and the study guide.
• See the OCR GCSE Physics hub and tick off topics on the checklist.
• Try the free 10-minute diagnostics.
• Book a free trial class.

Official syllabus

OCR, GCSE (9-1) Gateway Science Physics A (J249). Specification Version 5.0, July 2026; first assessment 2018. Topic P5.1 Wave behaviour, statements P5.1a to P5.1e, P5.1j and P5.1k.