# WPH12 Waves and Particle Nature of Light Topic Questions

> Edexcel IAL WPH12: every Waves and Particle Nature of Light topic question from 22 papers (2019–2026), grouped by syllabus point. 468 questions, 1138 marks,…

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Edexcel IAL · Physics · WPH12 · A Level

Every WPH12 Waves and Particle Nature of Light topic question from the 2018–current syllabus, drawn from 22 papers (2019–2026) and grouped by syllabus point. Each row opens a page listing the exact question numbers, marks and a direct link into the paper. These are questions by topic, not full papers, so you can revise one topic at a time.

- WPH12
- 31 subtopics
- 468 topic questions
- 22 papers
- 1,138 tagged marks
- [Back to Waves and Particle Nature of Light](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/)
- [All paper codes](https://www.examsci.com/topics/)

Core finding

**45 know and understand that at the interface between medium 1 and… is the most frequently assessed subtopic in Waves and Particle Nature of Light, with 56 topic questions and 147 marks across 22 papers.** 41 know what is meant by a standing/stationary wave and… follows with 43 topic questions and 114 marks. The topic contains 31 subtopics, 468 topic questions and 1,138 marks in total. Rows count only the parts tagged to that subtopic, keep the same colour in both charts and repeat paper count, tagged marks and year range in the native table.

## Topic question count and mark distribution

Subtopics are on the vertical axis and sorted from highest to lowest. Only the parts whose knowledge graph matches a subtopic are counted for it, and percentages are each row's share of the tagged total in that chart. A part tagged to several subtopics is counted in each bar, so the bars are not a partition of the topic total.

### Questions by subtopic

question items

- [45 know and understand that at the interface between medium 1 and medium 2 $n_{1}\sin \theta_{1}= n_{2}\sin \theta_{2}$ where refractive index is $n=\frac{c}{v}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/45-know-and-understand-that-at-the-interface-between-medium-1-and-medium-2-n-1-sin/) (22 papers) — 56 · 8.3%
- [41 know what is meant by a standing/stationary wave and understand how such a wave is formed, know how to identify nodes and antinodes](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/41-know-what-is-meant-by-a-standing-stationary-wave-and-understand-how-such-a-wave-is/) (20 papers) — 43 · 6.4%
- [60 understand the terms 'threshold frequency' and 'work function' and be able to use the equation $hf=\phi+\frac{1}{2}mv_{max}^{2}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/60-understand-the-terms-threshold-frequency-and-work-function-and-be-able-to-use-the/) (20 papers) — 38 · 5.7%
- [34 be able to use the wave equation $v=f\lambda$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/34-be-able-to-use-the-wave-equation-v-f-lambda/) (19 papers) — 36 · 5.4%
- [56 understand how a pulse-echo technique can provide information about the position of an object and how the amount of information obtained may be limited by the wavelength of the radiation or by the duration of pulses](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/56-understand-how-a-pulse-echo-technique-can-provide-information-about-the-position/) (20 papers) — 35 · 5.2%
- [58 be able to use the equation $E=hf$ that relates the photon energy to the wave frequency](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/58-be-able-to-use-the-equation-e-hf-that-relates-the-photon-energy-to-the-wave/) (21 papers) — 34 · 5.1%
- [39 know and understand what is meant by wavefront, coherence, path difference, superposition, interference and phase](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/39-know-and-understand-what-is-meant-by-wavefront-coherence-path-difference/) (19 papers) — 31 · 4.6%
- [63 understand atomic line spectra in terms of transitions between discrete energy levels and understand how to calculate the frequency of radiation that could be emitted or absorbed in a transition between energy levels.](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/63-understand-atomic-line-spectra-in-terms-of-transitions-between-discrete-energy/) (22 papers) — 29 · 4.3%
- [44 be able to use the equation for the intensity of radiation $I=\frac{P}{A}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/44-be-able-to-use-the-equation-for-the-intensity-of-radiation-i-frac-p-a/) (22 papers) — 28 · 4.2%
- [49 understand what is meant by plane polarisation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/49-understand-what-is-meant-by-plane-polarisation/) (19 papers) — 28 · 4.2%
- [51 be able to use $n\lambda= d\sin\theta$ for a diffraction grating](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/51-be-able-to-use-n-lambda-d-sin-theta-for-a-diffraction-grating/) (18 papers) — 28 · 4.2%
- [42 be able to use the equation for the speed of a transverse wave on a string $v=\sqrt{\frac{T}{\mu}}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/42-be-able-to-use-the-equation-for-the-speed-of-a-transverse-wave-on-a-string-v-sqrt/) (21 papers) — 27 · 4.0%
- [62 understand how the photoelectric effect provides evidence for the particle nature of electromagnetic radiation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/62-understand-how-the-photoelectric-effect-provides-evidence-for-the-particle-nature/) (20 papers) — 26 · 3.9%
- [47 be able to predict whether total internal reflection will occur at an interface](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/47-be-able-to-predict-whether-total-internal-reflection-will-occur-at-an-interface/) (18 papers) — 25 · 3.7%
- [37 be able to draw and interpret graphs representing transverse and longitudinal waves including standing/stationary waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/37-be-able-to-draw-and-interpret-graphs-representing-transverse-and-longitudinal/) (14 papers) — 22 · 3.3%
- [33 understand the terms amplitude, frequency, period, speed and wavelength](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/33-understand-the-terms-amplitude-frequency-period-speed-and-wavelength/) (14 papers) — 21 · 3.1%
- [61 be able to use the electronvolt (eV) to express small energies](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/61-be-able-to-use-the-electronvolt-ev-to-express-small-energies/) (19 papers) — 21 · 3.1%
- [46 be able to calculate critical angle using $\sin C=\frac{1}{n}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/46-be-able-to-calculate-critical-angle-using-sin-c-frac-1-n/) (15 papers) — 19 · 2.8%
- [54 be able to use the de Broglie equation $\lambda=\frac{h}{p}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/54-be-able-to-use-the-de-broglie-equation-lambda-frac-h-p/) (18 papers) — 19 · 2.8%
- [40 be able to use the relationship between phase difference and path difference](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/40-be-able-to-use-the-relationship-between-phase-difference-and-path-difference/) (16 papers) — 18 · 2.7%
- [36 be able to describe transverse waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/36-be-able-to-describe-transverse-waves/) (10 papers) — 11 · 1.6%
- [50 understand what is meant by diffraction and use Huygens' construction to explain what happens to a wave when it meets a slit or an obstacle](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/50-understand-what-is-meant-by-diffraction-and-use-huygens-construction-to-explain/) (8 papers) — 11 · 1.6%
- [55 understand that waves can be transmitted and reflected at an interface between media](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/55-understand-that-waves-can-be-transmitted-and-reflected-at-an-interface-between/) (8 papers) — 11 · 1.6%
- [35 be able to describe longitudinal waves in terms of pressure variation and the displacement of molecules](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/35-be-able-to-describe-longitudinal-waves-in-terms-of-pressure-variation-and-the/) (9 papers) — 10 · 1.5%
- [38 CORE PRACTICAL 4: Determine the speed of sound in air using a 2-beam oscilloscope, signal generator, speaker and microphone](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/38-core-practical-4-determine-the-speed-of-sound-in-air-using-a-2-beam-oscilloscope/) (5 papers) — 8 · 1.2%
- [57 understand how the behaviour of electromagnetic radiation can be described in terms of a wave model and a photon model, and how these models developed over time](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/57-understand-how-the-behaviour-of-electromagnetic-radiation-can-be-described-in/) (6 papers) — 8 · 1.2%
- [59 understand that the absorption of a photon can result in the emission of a photoelectron](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/59-understand-that-the-absorption-of-a-photon-can-result-in-the-emission-of-a/) (7 papers) — 8 · 1.2%
- [52 CORE PRACTICAL 6: Determine the wavelength of light from a laser or other light source using a diffraction grating](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/52-core-practical-6-determine-the-wavelength-of-light-from-a-laser-or-other-light/) (5 papers) — 7 · 1.0%
- [43 CORE PRACTICAL 5: Investigate the effects of length, tension and mass per unit length on the frequency of a vibrating string or wire](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/43-core-practical-5-investigate-the-effects-of-length-tension-and-mass-per-unit/) (4 papers) — 6 · 0.9%
- [53 understand how diffraction experiments provide evidence for the wave nature of electrons](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/53-understand-how-diffraction-experiments-provide-evidence-for-the-wave-nature-of/) (6 papers) — 6 · 0.9%
- [48 understand how to measure the refractive index of a solid material](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/48-understand-how-to-measure-the-refractive-index-of-a-solid-material/) (1 papers) — 1 · 0.1%

### Marks by subtopic

marks

- [45 know and understand that at the interface between medium 1 and medium 2 $n_{1}\sin \theta_{1}= n_{2}\sin \theta_{2}$ where refractive index is $n=\frac{c}{v}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/45-know-and-understand-that-at-the-interface-between-medium-1-and-medium-2-n-1-sin/) (22 papers) — 147 · 8.0%
- [60 understand the terms 'threshold frequency' and 'work function' and be able to use the equation $hf=\phi+\frac{1}{2}mv_{max}^{2}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/60-understand-the-terms-threshold-frequency-and-work-function-and-be-able-to-use-the/) (20 papers) — 128 · 7.0%
- [58 be able to use the equation $E=hf$ that relates the photon energy to the wave frequency](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/58-be-able-to-use-the-equation-e-hf-that-relates-the-photon-energy-to-the-wave/) (21 papers) — 124 · 6.8%
- [34 be able to use the wave equation $v=f\lambda$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/34-be-able-to-use-the-wave-equation-v-f-lambda/) (19 papers) — 117 · 6.4%
- [41 know what is meant by a standing/stationary wave and understand how such a wave is formed, know how to identify nodes and antinodes](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/41-know-what-is-meant-by-a-standing-stationary-wave-and-understand-how-such-a-wave-is/) (20 papers) — 114 · 6.2%
- [62 understand how the photoelectric effect provides evidence for the particle nature of electromagnetic radiation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/62-understand-how-the-photoelectric-effect-provides-evidence-for-the-particle-nature/) (20 papers) — 92 · 5.0%
- [39 know and understand what is meant by wavefront, coherence, path difference, superposition, interference and phase](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/39-know-and-understand-what-is-meant-by-wavefront-coherence-path-difference/) (19 papers) — 91 · 5.0%
- [56 understand how a pulse-echo technique can provide information about the position of an object and how the amount of information obtained may be limited by the wavelength of the radiation or by the duration of pulses](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/56-understand-how-a-pulse-echo-technique-can-provide-information-about-the-position/) (20 papers) — 82 · 4.5%
- [42 be able to use the equation for the speed of a transverse wave on a string $v=\sqrt{\frac{T}{\mu}}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/42-be-able-to-use-the-equation-for-the-speed-of-a-transverse-wave-on-a-string-v-sqrt/) (21 papers) — 78 · 4.2%
- [61 be able to use the electronvolt (eV) to express small energies](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/61-be-able-to-use-the-electronvolt-ev-to-express-small-energies/) (19 papers) — 77 · 4.2%
- [44 be able to use the equation for the intensity of radiation $I=\frac{P}{A}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/44-be-able-to-use-the-equation-for-the-intensity-of-radiation-i-frac-p-a/) (22 papers) — 69 · 3.8%
- [47 be able to predict whether total internal reflection will occur at an interface](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/47-be-able-to-predict-whether-total-internal-reflection-will-occur-at-an-interface/) (18 papers) — 69 · 3.8%
- [63 understand atomic line spectra in terms of transitions between discrete energy levels and understand how to calculate the frequency of radiation that could be emitted or absorbed in a transition between energy levels.](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/63-understand-atomic-line-spectra-in-terms-of-transitions-between-discrete-energy/) (22 papers) — 68 · 3.7%
- [51 be able to use $n\lambda= d\sin\theta$ for a diffraction grating](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/51-be-able-to-use-n-lambda-d-sin-theta-for-a-diffraction-grating/) (18 papers) — 67 · 3.6%
- [46 be able to calculate critical angle using $\sin C=\frac{1}{n}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/46-be-able-to-calculate-critical-angle-using-sin-c-frac-1-n/) (15 papers) — 61 · 3.3%
- [49 understand what is meant by plane polarisation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/49-understand-what-is-meant-by-plane-polarisation/) (19 papers) — 58 · 3.2%
- [37 be able to draw and interpret graphs representing transverse and longitudinal waves including standing/stationary waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/37-be-able-to-draw-and-interpret-graphs-representing-transverse-and-longitudinal/) (14 papers) — 47 · 2.6%
- [40 be able to use the relationship between phase difference and path difference](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/40-be-able-to-use-the-relationship-between-phase-difference-and-path-difference/) (16 papers) — 45 · 2.5%
- [54 be able to use the de Broglie equation $\lambda=\frac{h}{p}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/54-be-able-to-use-the-de-broglie-equation-lambda-frac-h-p/) (18 papers) — 42 · 2.3%
- [33 understand the terms amplitude, frequency, period, speed and wavelength](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/33-understand-the-terms-amplitude-frequency-period-speed-and-wavelength/) (14 papers) — 37 · 2.0%
- [59 understand that the absorption of a photon can result in the emission of a photoelectron](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/59-understand-that-the-absorption-of-a-photon-can-result-in-the-emission-of-a/) (7 papers) — 33 · 1.8%
- [57 understand how the behaviour of electromagnetic radiation can be described in terms of a wave model and a photon model, and how these models developed over time](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/57-understand-how-the-behaviour-of-electromagnetic-radiation-can-be-described-in/) (6 papers) — 30 · 1.6%
- [50 understand what is meant by diffraction and use Huygens' construction to explain what happens to a wave when it meets a slit or an obstacle](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/50-understand-what-is-meant-by-diffraction-and-use-huygens-construction-to-explain/) (8 papers) — 29 · 1.6%
- [38 CORE PRACTICAL 4: Determine the speed of sound in air using a 2-beam oscilloscope, signal generator, speaker and microphone](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/38-core-practical-4-determine-the-speed-of-sound-in-air-using-a-2-beam-oscilloscope/) (5 papers) — 25 · 1.4%
- [55 understand that waves can be transmitted and reflected at an interface between media](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/55-understand-that-waves-can-be-transmitted-and-reflected-at-an-interface-between/) (8 papers) — 22 · 1.2%
- [36 be able to describe transverse waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/36-be-able-to-describe-transverse-waves/) (10 papers) — 20 · 1.1%
- [43 CORE PRACTICAL 5: Investigate the effects of length, tension and mass per unit length on the frequency of a vibrating string or wire](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/43-core-practical-5-investigate-the-effects-of-length-tension-and-mass-per-unit/) (4 papers) — 17 · 0.9%
- [52 CORE PRACTICAL 6: Determine the wavelength of light from a laser or other light source using a diffraction grating](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/52-core-practical-6-determine-the-wavelength-of-light-from-a-laser-or-other-light/) (5 papers) — 17 · 0.9%
- [35 be able to describe longitudinal waves in terms of pressure variation and the displacement of molecules](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/35-be-able-to-describe-longitudinal-waves-in-terms-of-pressure-variation-and-the/) (9 papers) — 15 · 0.8%
- [53 understand how diffraction experiments provide evidence for the wave nature of electrons](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/53-understand-how-diffraction-experiments-provide-evidence-for-the-wave-nature-of/) (6 papers) — 12 · 0.7%
- [48 understand how to measure the refractive index of a solid material](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/48-understand-how-to-measure-the-refractive-index-of-a-solid-material/) (1 papers) — 3 · 0.2%

## Subtopic comparison matrix

Curriculum order is by syllabus number, then alphabetically. Every row links to the matching past-paper question list.

| Subtopic | Topic questions | Papers | Marks | Years | |
| --- | --- | --- | --- | --- | --- |
| **[33 understand the terms amplitude, frequency, period, speed and wavelength](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/33-understand-the-terms-amplitude-frequency-period-speed-and-wavelength/)** | 21 | 14 | 37 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/33-understand-the-terms-amplitude-frequency-period-speed-and-wavelength/) |
| **[34 be able to use the wave equation $v=f\lambda$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/34-be-able-to-use-the-wave-equation-v-f-lambda/)** | 36 | 19 | 117 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/34-be-able-to-use-the-wave-equation-v-f-lambda/) |
| **[35 be able to describe longitudinal waves in terms of pressure variation and the displacement of molecules](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/35-be-able-to-describe-longitudinal-waves-in-terms-of-pressure-variation-and-the/)** | 10 | 9 | 15 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/35-be-able-to-describe-longitudinal-waves-in-terms-of-pressure-variation-and-the/) |
| **[36 be able to describe transverse waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/36-be-able-to-describe-transverse-waves/)** | 11 | 10 | 20 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/36-be-able-to-describe-transverse-waves/) |
| **[37 be able to draw and interpret graphs representing transverse and longitudinal waves including standing/stationary waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/37-be-able-to-draw-and-interpret-graphs-representing-transverse-and-longitudinal/)** | 22 | 14 | 47 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/37-be-able-to-draw-and-interpret-graphs-representing-transverse-and-longitudinal/) |
| **[38 CORE PRACTICAL 4: Determine the speed of sound in air using a 2-beam oscilloscope, signal generator, speaker and microphone](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/38-core-practical-4-determine-the-speed-of-sound-in-air-using-a-2-beam-oscilloscope/)** | 8 | 5 | 25 | 2019–2024 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/38-core-practical-4-determine-the-speed-of-sound-in-air-using-a-2-beam-oscilloscope/) |
| **[39 know and understand what is meant by wavefront, coherence, path difference, superposition, interference and phase](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/39-know-and-understand-what-is-meant-by-wavefront-coherence-path-difference/)** | 31 | 19 | 91 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/39-know-and-understand-what-is-meant-by-wavefront-coherence-path-difference/) |
| **[40 be able to use the relationship between phase difference and path difference](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/40-be-able-to-use-the-relationship-between-phase-difference-and-path-difference/)** | 18 | 16 | 45 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/40-be-able-to-use-the-relationship-between-phase-difference-and-path-difference/) |
| **[41 know what is meant by a standing/stationary wave and understand how such a wave is formed, know how to identify nodes and antinodes](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/41-know-what-is-meant-by-a-standing-stationary-wave-and-understand-how-such-a-wave-is/)** | 43 | 20 | 114 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/41-know-what-is-meant-by-a-standing-stationary-wave-and-understand-how-such-a-wave-is/) |
| **[42 be able to use the equation for the speed of a transverse wave on a string $v=\sqrt{\frac{T}{\mu}}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/42-be-able-to-use-the-equation-for-the-speed-of-a-transverse-wave-on-a-string-v-sqrt/)** | 27 | 21 | 78 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/42-be-able-to-use-the-equation-for-the-speed-of-a-transverse-wave-on-a-string-v-sqrt/) |
| **[43 CORE PRACTICAL 5: Investigate the effects of length, tension and mass per unit length on the frequency of a vibrating string or wire](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/43-core-practical-5-investigate-the-effects-of-length-tension-and-mass-per-unit/)** | 6 | 4 | 17 | 2019–2025 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/43-core-practical-5-investigate-the-effects-of-length-tension-and-mass-per-unit/) |
| **[44 be able to use the equation for the intensity of radiation $I=\frac{P}{A}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/44-be-able-to-use-the-equation-for-the-intensity-of-radiation-i-frac-p-a/)** | 28 | 22 | 69 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/44-be-able-to-use-the-equation-for-the-intensity-of-radiation-i-frac-p-a/) |
| **[45 know and understand that at the interface between medium 1 and medium 2 $n_{1}\sin \theta_{1}= n_{2}\sin \theta_{2}$ where refractive index is $n=\frac{c}{v}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/45-know-and-understand-that-at-the-interface-between-medium-1-and-medium-2-n-1-sin/)** | 56 | 22 | 147 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/45-know-and-understand-that-at-the-interface-between-medium-1-and-medium-2-n-1-sin/) |
| **[46 be able to calculate critical angle using $\sin C=\frac{1}{n}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/46-be-able-to-calculate-critical-angle-using-sin-c-frac-1-n/)** | 19 | 15 | 61 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/46-be-able-to-calculate-critical-angle-using-sin-c-frac-1-n/) |
| **[47 be able to predict whether total internal reflection will occur at an interface](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/47-be-able-to-predict-whether-total-internal-reflection-will-occur-at-an-interface/)** | 25 | 18 | 69 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/47-be-able-to-predict-whether-total-internal-reflection-will-occur-at-an-interface/) |
| **[48 understand how to measure the refractive index of a solid material](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/48-understand-how-to-measure-the-refractive-index-of-a-solid-material/)** | 1 | 1 | 3 | 2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/48-understand-how-to-measure-the-refractive-index-of-a-solid-material/) |
| **[49 understand what is meant by plane polarisation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/49-understand-what-is-meant-by-plane-polarisation/)** | 28 | 19 | 58 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/49-understand-what-is-meant-by-plane-polarisation/) |
| **[50 understand what is meant by diffraction and use Huygens' construction to explain what happens to a wave when it meets a slit or an obstacle](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/50-understand-what-is-meant-by-diffraction-and-use-huygens-construction-to-explain/)** | 11 | 8 | 29 | 2020–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/50-understand-what-is-meant-by-diffraction-and-use-huygens-construction-to-explain/) |
| **[51 be able to use $n\lambda= d\sin\theta$ for a diffraction grating](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/51-be-able-to-use-n-lambda-d-sin-theta-for-a-diffraction-grating/)** | 28 | 18 | 67 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/51-be-able-to-use-n-lambda-d-sin-theta-for-a-diffraction-grating/) |
| **[52 CORE PRACTICAL 6: Determine the wavelength of light from a laser or other light source using a diffraction grating](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/52-core-practical-6-determine-the-wavelength-of-light-from-a-laser-or-other-light/)** | 7 | 5 | 17 | 2020–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/52-core-practical-6-determine-the-wavelength-of-light-from-a-laser-or-other-light/) |
| **[53 understand how diffraction experiments provide evidence for the wave nature of electrons](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/53-understand-how-diffraction-experiments-provide-evidence-for-the-wave-nature-of/)** | 6 | 6 | 12 | 2020–2024 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/53-understand-how-diffraction-experiments-provide-evidence-for-the-wave-nature-of/) |
| **[54 be able to use the de Broglie equation $\lambda=\frac{h}{p}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/54-be-able-to-use-the-de-broglie-equation-lambda-frac-h-p/)** | 19 | 18 | 42 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/54-be-able-to-use-the-de-broglie-equation-lambda-frac-h-p/) |
| **[55 understand that waves can be transmitted and reflected at an interface between media](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/55-understand-that-waves-can-be-transmitted-and-reflected-at-an-interface-between/)** | 11 | 8 | 22 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/55-understand-that-waves-can-be-transmitted-and-reflected-at-an-interface-between/) |
| **[56 understand how a pulse-echo technique can provide information about the position of an object and how the amount of information obtained may be limited by the wavelength of the radiation or by the duration of pulses](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/56-understand-how-a-pulse-echo-technique-can-provide-information-about-the-position/)** | 35 | 20 | 82 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/56-understand-how-a-pulse-echo-technique-can-provide-information-about-the-position/) |
| **[57 understand how the behaviour of electromagnetic radiation can be described in terms of a wave model and a photon model, and how these models developed over time](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/57-understand-how-the-behaviour-of-electromagnetic-radiation-can-be-described-in/)** | 8 | 6 | 30 | 2019–2025 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/57-understand-how-the-behaviour-of-electromagnetic-radiation-can-be-described-in/) |
| **[58 be able to use the equation $E=hf$ that relates the photon energy to the wave frequency](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/58-be-able-to-use-the-equation-e-hf-that-relates-the-photon-energy-to-the-wave/)** | 34 | 21 | 124 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/58-be-able-to-use-the-equation-e-hf-that-relates-the-photon-energy-to-the-wave/) |
| **[59 understand that the absorption of a photon can result in the emission of a photoelectron](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/59-understand-that-the-absorption-of-a-photon-can-result-in-the-emission-of-a/)** | 8 | 7 | 33 | 2020–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/59-understand-that-the-absorption-of-a-photon-can-result-in-the-emission-of-a/) |
| **[60 understand the terms 'threshold frequency' and 'work function' and be able to use the equation $hf=\phi+\frac{1}{2}mv_{max}^{2}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/60-understand-the-terms-threshold-frequency-and-work-function-and-be-able-to-use-the/)** | 38 | 20 | 128 | 2020–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/60-understand-the-terms-threshold-frequency-and-work-function-and-be-able-to-use-the/) |
| **[61 be able to use the electronvolt (eV) to express small energies](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/61-be-able-to-use-the-electronvolt-ev-to-express-small-energies/)** | 21 | 19 | 77 | 2019–2025 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/61-be-able-to-use-the-electronvolt-ev-to-express-small-energies/) |
| **[62 understand how the photoelectric effect provides evidence for the particle nature of electromagnetic radiation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/62-understand-how-the-photoelectric-effect-provides-evidence-for-the-particle-nature/)** | 26 | 20 | 92 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/62-understand-how-the-photoelectric-effect-provides-evidence-for-the-particle-nature/) |
| **[63 understand atomic line spectra in terms of transitions between discrete energy levels and understand how to calculate the frequency of radiation that could be emitted or absorbed in a transition between energy levels.](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/63-understand-atomic-line-spectra-in-terms-of-transitions-between-discrete-energy/)** | 29 | 22 | 68 | 2019–2026 | [Open topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/63-understand-atomic-line-spectra-in-terms-of-transitions-between-discrete-energy/) |

## Browse every topic question

- [33 understand the terms amplitude, frequency, period, speed and wavelength](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/33-understand-the-terms-amplitude-frequency-period-speed-and-wavelength/) — 21 question items · 14 papers — 37 marks · 2019–2026
- [34 be able to use the wave equation $v=f\lambda$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/34-be-able-to-use-the-wave-equation-v-f-lambda/) — 36 question items · 19 papers — 117 marks · 2019–2026
- [35 be able to describe longitudinal waves in terms of pressure variation and the displacement of molecules](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/35-be-able-to-describe-longitudinal-waves-in-terms-of-pressure-variation-and-the/) — 10 question items · 9 papers — 15 marks · 2019–2026
- [36 be able to describe transverse waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/36-be-able-to-describe-transverse-waves/) — 11 question items · 10 papers — 20 marks · 2019–2026
- [37 be able to draw and interpret graphs representing transverse and longitudinal waves including standing/stationary waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/37-be-able-to-draw-and-interpret-graphs-representing-transverse-and-longitudinal/) — 22 question items · 14 papers — 47 marks · 2019–2026
- [38 CORE PRACTICAL 4: Determine the speed of sound in air using a 2-beam oscilloscope, signal generator, speaker and microphone](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/38-core-practical-4-determine-the-speed-of-sound-in-air-using-a-2-beam-oscilloscope/) — 8 question items · 5 papers — 25 marks · 2019–2024
- [39 know and understand what is meant by wavefront, coherence, path difference, superposition, interference and phase](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/39-know-and-understand-what-is-meant-by-wavefront-coherence-path-difference/) — 31 question items · 19 papers — 91 marks · 2019–2026
- [40 be able to use the relationship between phase difference and path difference](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/40-be-able-to-use-the-relationship-between-phase-difference-and-path-difference/) — 18 question items · 16 papers — 45 marks · 2019–2026
- [41 know what is meant by a standing/stationary wave and understand how such a wave is formed, know how to identify nodes and antinodes](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/41-know-what-is-meant-by-a-standing-stationary-wave-and-understand-how-such-a-wave-is/) — 43 question items · 20 papers — 114 marks · 2019–2026
- [42 be able to use the equation for the speed of a transverse wave on a string $v=\sqrt{\frac{T}{\mu}}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/42-be-able-to-use-the-equation-for-the-speed-of-a-transverse-wave-on-a-string-v-sqrt/) — 27 question items · 21 papers — 78 marks · 2019–2026
- [43 CORE PRACTICAL 5: Investigate the effects of length, tension and mass per unit length on the frequency of a vibrating string or wire](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/43-core-practical-5-investigate-the-effects-of-length-tension-and-mass-per-unit/) — 6 question items · 4 papers — 17 marks · 2019–2025
- [44 be able to use the equation for the intensity of radiation $I=\frac{P}{A}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/44-be-able-to-use-the-equation-for-the-intensity-of-radiation-i-frac-p-a/) — 28 question items · 22 papers — 69 marks · 2019–2026
- [45 know and understand that at the interface between medium 1 and medium 2 $n_{1}\sin \theta_{1}= n_{2}\sin \theta_{2}$ where refractive index is $n=\frac{c}{v}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/45-know-and-understand-that-at-the-interface-between-medium-1-and-medium-2-n-1-sin/) — 56 question items · 22 papers — 147 marks · 2019–2026
- [46 be able to calculate critical angle using $\sin C=\frac{1}{n}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/46-be-able-to-calculate-critical-angle-using-sin-c-frac-1-n/) — 19 question items · 15 papers — 61 marks · 2019–2026
- [47 be able to predict whether total internal reflection will occur at an interface](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/47-be-able-to-predict-whether-total-internal-reflection-will-occur-at-an-interface/) — 25 question items · 18 papers — 69 marks · 2019–2026
- [48 understand how to measure the refractive index of a solid material](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/48-understand-how-to-measure-the-refractive-index-of-a-solid-material/) — 1 question items · 1 papers — 3 marks · 2026
- [49 understand what is meant by plane polarisation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/49-understand-what-is-meant-by-plane-polarisation/) — 28 question items · 19 papers — 58 marks · 2019–2026
- [50 understand what is meant by diffraction and use Huygens' construction to explain what happens to a wave when it meets a slit or an obstacle](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/50-understand-what-is-meant-by-diffraction-and-use-huygens-construction-to-explain/) — 11 question items · 8 papers — 29 marks · 2020–2026
- [51 be able to use $n\lambda= d\sin\theta$ for a diffraction grating](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/51-be-able-to-use-n-lambda-d-sin-theta-for-a-diffraction-grating/) — 28 question items · 18 papers — 67 marks · 2019–2026
- [52 CORE PRACTICAL 6: Determine the wavelength of light from a laser or other light source using a diffraction grating](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/52-core-practical-6-determine-the-wavelength-of-light-from-a-laser-or-other-light/) — 7 question items · 5 papers — 17 marks · 2020–2026
- [53 understand how diffraction experiments provide evidence for the wave nature of electrons](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/53-understand-how-diffraction-experiments-provide-evidence-for-the-wave-nature-of/) — 6 question items · 6 papers — 12 marks · 2020–2024
- [54 be able to use the de Broglie equation $\lambda=\frac{h}{p}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/54-be-able-to-use-the-de-broglie-equation-lambda-frac-h-p/) — 19 question items · 18 papers — 42 marks · 2019–2026
- [55 understand that waves can be transmitted and reflected at an interface between media](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/55-understand-that-waves-can-be-transmitted-and-reflected-at-an-interface-between/) — 11 question items · 8 papers — 22 marks · 2019–2026
- [56 understand how a pulse-echo technique can provide information about the position of an object and how the amount of information obtained may be limited by the wavelength of the radiation or by the duration of pulses](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/56-understand-how-a-pulse-echo-technique-can-provide-information-about-the-position/) — 35 question items · 20 papers — 82 marks · 2019–2026
- [57 understand how the behaviour of electromagnetic radiation can be described in terms of a wave model and a photon model, and how these models developed over time](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/57-understand-how-the-behaviour-of-electromagnetic-radiation-can-be-described-in/) — 8 question items · 6 papers — 30 marks · 2019–2025
- [58 be able to use the equation $E=hf$ that relates the photon energy to the wave frequency](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/58-be-able-to-use-the-equation-e-hf-that-relates-the-photon-energy-to-the-wave/) — 34 question items · 21 papers — 124 marks · 2019–2026
- [59 understand that the absorption of a photon can result in the emission of a photoelectron](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/59-understand-that-the-absorption-of-a-photon-can-result-in-the-emission-of-a/) — 8 question items · 7 papers — 33 marks · 2020–2026
- [60 understand the terms 'threshold frequency' and 'work function' and be able to use the equation $hf=\phi+\frac{1}{2}mv_{max}^{2}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/60-understand-the-terms-threshold-frequency-and-work-function-and-be-able-to-use-the/) — 38 question items · 20 papers — 128 marks · 2020–2026
- [61 be able to use the electronvolt (eV) to express small energies](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/61-be-able-to-use-the-electronvolt-ev-to-express-small-energies/) — 21 question items · 19 papers — 77 marks · 2019–2025
- [62 understand how the photoelectric effect provides evidence for the particle nature of electromagnetic radiation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/62-understand-how-the-photoelectric-effect-provides-evidence-for-the-particle-nature/) — 26 question items · 20 papers — 92 marks · 2019–2026
- [63 understand atomic line spectra in terms of transitions between discrete energy levels and understand how to calculate the frequency of radiation that could be emitted or absorbed in a transition between energy levels.](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/63-understand-atomic-line-spectra-in-terms-of-transitions-between-discrete-energy/) — 29 question items · 22 papers — 68 marks · 2019–2026

## Other topics in WPH12

- [Electric Circuits 268 question items](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/electric-circuits/)

## Topic question rules and edge cases

**How many subtopics does Waves and Particle Nature of Light contain?**

This page lists 31 subtopics tagged to the current syllabus. They are ordered by syllabus number, then alphabetically, and each row opens a page of matching past-paper questions.

**How are the subtopic question and mark totals calculated?**

A multiple-choice question contributes one item and its marks to every subtopic it is tagged with. A structured question contributes one item per tagged part, and that part’s marks; untagged parts of the same question are not counted here. A part tagged to several subtopics therefore appears under each of them.

**Why do some subtopics have no numbered prefix?**

Practical-skills statements and some syllabus bullets are unnumbered. Numbered statements come first; unnumbered statements and ties are sorted alphabetically.

**Is the LaTeX rendered without JavaScript?**

Yes. Subtopics that contain formulas are converted to static KaTeX HTML during the build, and the KaTeX stylesheet is served from the same site.

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