AQA GCSE Physics 8463: Waves – 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 Topic 6, Waves (sections 4.6.1 to 4.6.3), of the AQA GCSE Physics (8463) specification, for first teaching 2016 with exams from June 2018 (version 1.1). Waves is examined on Paper 2 at Foundation and Higher tier every May/June. Questions or parts testing “(HT only)” statements are labelled (Higher tier only); everything else is for both tiers. Take the speed of electromagnetic waves in air as 3.0 × 10⁸ m/s.

Learn the content first in the study guide and the revision notes. The course hub is AQA GCSE Physics and the printable checklist lists every statement.

Questions

1. Waves can be transverse or longitudinal.

(a) Describe the difference between a transverse wave and a longitudinal wave. [2] (b) Give one example of each type of wave. [2] (c) Describe what you would see that shows it is the wave, and not the water, that travels across a pond. [2]

2. A graph of displacement against distance for a wave on a spring shows crests at +3.0 cm and troughs at −3.0 cm. Exactly 2.5 complete waves fit into a distance of 1.5 m. The frequency is 8.0 Hz.

(a) State the amplitude of the wave. [1] (b) Calculate the wavelength. [1] (c) Calculate the wave speed. [2] (d) Calculate the period. Use the equation sheet. [2]

3. A student uses a ripple tank with a lamp above it.

(a) Explain why the student measures 10 waves rather than one. [2] (b) 10 waves measure 27 cm. 15 waves pass a fixed point in 5.0 s. Calculate the speed of the ripples in m/s. [3]

4. Two students stand 240 m apart on a field. One bangs two blocks together. The other starts a stopwatch on seeing the blocks meet and stops it on hearing the sound. The time recorded is 0.75 s.

(a) Calculate the speed of sound from these results. [2] (b) Suggest two improvements to the method. [2]

5. A 2.0 kHz sound passes from air into a steel rail. The speed of sound is 340 m/s in air and 5100 m/s in steel.

(a) State what happens to the frequency of the sound as it enters the steel. [1] (b) Calculate the wavelength of the sound in the steel. [2]

6. (Higher tier only)

(a) State the range of normal human hearing. [1] (b) Explain why a person cannot hear a whistle that produces 25 kHz. [2] (c) An ultrasound pulse is sent into a steel beam to look for cracks. Ultrasound travels at 6000 m/s in the steel. An echo from a crack returns 15 μs after the pulse is sent. Calculate the depth of the crack in cm. [3]

7. (Higher tier only)

(a) Explain how seismic waves provide evidence that part of the Earth’s core is liquid. [4] (b) A ship uses echo sounding. A pulse travels at 1500 m/s in seawater and returns after 0.84 s. Calculate the depth of the water. [3]

8. A ray of light passes from air into a glass block at an angle to the normal.

(a) Describe how the direction of the ray changes as it enters the glass. [1] (b) (Higher tier only) Use ideas about wave fronts to explain why the ray changes direction. [3] (c) Describe the difference between specular and diffuse reflection. [2] (d) Give one safety precaution when using a ray box in Required practical 9. [1]

9.

(a) Define the focal length of a convex lens. [1] (b) A convex lens gives a magnification of 4.0. The object is 1.5 cm tall. Calculate the height of the image. [2] (c) State whether the image formed by a concave lens can be real. [1] (d) A green shirt is lit with white light and viewed through a red filter. Explain what colour the shirt appears. [3]

10.

(a) Name the group of the electromagnetic spectrum between visible light and X-rays. [1] (b) A wireless router emits microwaves with a frequency of 2.4 GHz. Calculate their wavelength. [3] (c) (Higher tier only) A radio transmitter produces waves of frequency 150 MHz. Explain how these waves can produce a signal in a receiving aerial, and state the frequency of that signal. [2]

11. The table gives the radiation dose from two medical procedures.

Procedure	Dose (mSv)
Chest X-ray	0.02
CT scan of the abdomen	8

(a) Convert the dose from the CT scan into sieverts. [1] (b) Calculate how many chest X-rays give the same dose as one CT scan. [2] (c) Explain why X-rays can harm the body, and suggest why a doctor may still recommend a CT scan. [3]

12. This question is about infrared radiation.

(a) Describe how to use a Leslie cube to compare the infrared radiation emitted by different surfaces. [4] (b) Name the type of surface that emits the most infrared. [1] (c) Describe a perfect black body. [2] (d) (Higher tier only) The Earth’s temperature is roughly constant. Explain what would happen to its temperature if the Earth kept absorbing radiation at the same rate but less radiation escaped into space. [3]

Answers

1. (a) Transverse: oscillations perpendicular to the direction of energy transfer [1]. Longitudinal: oscillations parallel to the direction of energy transfer [1]. (b) Transverse: ripples on water or any electromagnetic wave [1]. Longitudinal: sound in air [1]. (c) A floating object bobs up and down as the ripples pass [1] but does not move along with the waves [1]. [6] Examiner insight: “Up and down” versus “side to side” earns nothing without a reference to the direction of energy transfer.

2. (a) 3.0 cm [1] (b) λ = 1.5 / 2.5 = 0.60 m [1] (c) v = f λ = 8.0 × 0.60 [1] = 4.8 m/s [1] (d) T = 1/f = 1/8.0 [1] = 0.125 s [1] [6] Examiner insight: An amplitude of 6.0 cm (crest to trough) scores zero; later parts are marked with error carried forward if you slip earlier.

3. (a) One wave is short, so its percentage uncertainty is large [1]; measuring 10 and dividing by 10 reduces it [1]. (b) λ = 27 / 10 = 2.7 cm = 0.027 m [1]; f = 15 / 5.0 = 3.0 Hz [1]; v = 3.0 × 0.027 = 0.081 m/s [1] [5] Examiner insight: The unit requested is m/s; leaving λ in cm gives 8.1 and loses the final mark unless you convert.

4. (a) v = distance / time = 240 / 0.75 [1] = 320 m/s [1] (b) Repeat and take a mean [1]; use a larger distance so reaction time is a smaller fraction of the total time [1]. (Also allow: use several timers and average their readings.) [4] Examiner insight: “Be more accurate” gets no credit; each improvement must say what you would change.

5. (a) It stays the same [1]. (b) λ = v / f = 5100 / 2000 [1] = 2.55 m [1] [3] Examiner insight: Using 2.0 instead of 2000 Hz gives 2550 m; convert kHz before substituting.

6. (a) 20 Hz to 20 kHz [1] (b) 25 kHz is above 20 kHz / the upper limit [1]; the ear drum and other parts cannot convert vibrations at such a high frequency into the sensation of sound [1]. (c) Total distance = 6000 × 15 × 10⁻⁶ = 0.090 m [1]; depth = 0.090 / 2 [1] = 0.045 m = 4.5 cm [1] [6] Examiner insight: The halving step carries its own mark, so show it even if you do it mentally.

7. (a) S-waves are transverse [1] and cannot travel through liquids [1]. S-waves are not detected on the opposite side of the Earth from an earthquake [1], so part of the core must be liquid [1]. (b) Distance = 1500 × 0.84 = 1260 m [1]; depth = 1260 / 2 [1] = 630 m [1] [7] Examiner insight: In (a) the conclusion “liquid core” alone earns one mark; the evidence chain earns the rest.

8. (a) It bends towards the normal [1]. (b) Light travels more slowly in glass [1]. One end of each wave front enters the glass first and slows down while the rest is still moving faster [1], so the wave front changes direction [1]. (c) Specular: reflection from a smooth surface in a single direction [1]. Diffuse: reflection from a rough surface, scattered in many directions [1]. (d) The ray box gets hot: let it cool before moving it / do not touch the lamp housing [1]. [7] Examiner insight: For (b), “it slows down” alone is one mark; you must say that different parts of the wave front change speed at different times.

9. (a) The distance from the lens to the principal focus [1]. (b) image height = 4.0 × 1.5 [1] = 6.0 cm [1] (c) No; it is always virtual [1]. (d) The shirt reflects only green light [1]. The red filter absorbs green light / transmits only red [1], so no light reaches the eye and the shirt appears black [1]. [7] Examiner insight: “Black” with no reasoning scores only the final mark; name what the shirt reflects and what the filter absorbs.

10. (a) Ultraviolet [1] (b) f = 2.4 × 10⁹ Hz [1]; λ = v / f = 3.0 × 10⁸ / 2.4 × 10⁹ [1] = 0.125 m [1] (c) The radio waves are absorbed by the aerial and create an alternating current in it [1] with the same frequency, 150 MHz [1]. [6] Examiner insight: The conversion of GHz to Hz is often a separate mark; 0.125 written as 1.25 or 12.5 loses the accuracy mark.

11. (a) 8 / 1000 = 0.008 Sv [1] (b) 8 / 0.02 [1] = 400 [1] (c) X-rays are ionising [1] and can cause mutation of genes and cancer [1]. The benefit of diagnosing a serious condition outweighs the small increase in risk [1]. [6] Examiner insight: A “suggest” here needs a risk-versus-benefit comparison; “the dose is small” alone is not enough.

12. (a) Fill the cube with hot water [1]. Place an infrared detector (or thermometer) facing one surface [1] at the same distance from each surface in turn [1]. Record and compare the readings for each surface [1]. (b) Matt black [1] (c) It absorbs all the radiation that falls on it, reflecting and transmitting none [1]; it is the best possible emitter [1]. (d) The Earth would absorb radiation faster than it emits it [1], so its temperature would rise [1] until the rate of emission increased to equal the rate of absorption again [1]. [10] Examiner insight: In (a), the control variable (same distance) is a separate mark; “measure the heat” without a named instrument gains little.

Where marks are usually lost

• Amplitude taken from crest to trough.
• Echo, ultrasound and sonar distances not halved.
• Prefixes (kHz, MHz, GHz, μs) not converted before calculating.
• Claiming frequency changes when a wave enters a new medium.
• Seismic answers that say “S-waves stop” without stating they are transverse and cannot pass through liquid.
• Colour answers that give only the final colour with no reflection/absorption reasoning.
• Radiation answers that say “dangerous” without “ionising”, “mutation” or “cancer”.
• Black body answers that miss “best possible emitter”.

Next steps

• Waves revision notes
• Waves study guide
• Magnetism and electromagnetism practice questions
• AQA GCSE Physics course hub
• Printable checklist
• All free 10-minute diagnostics
• Book a free trial class

Official syllabus

AQA GCSE Physics (8463) specification, for first teaching 2016, exams from June 2018, version 1.1 (30 September 2019), published by AQA – section 4.6 Waves.