Light and the Electromagnetic Spectrum | Edexcel GCSE Physics, Higher tier (1PH0)
Light and the Electromagnetic Spectrum
- 194 questions
- 13 subtopics
- Paper 1
- Paper 1
Light and the Electromagnetic Spectrum is examined in Paper 1, Physics 1.
It covers reflection, refraction and total internal reflection, why objects appear coloured, lenses, ray diagrams and images, properties of electromagnetic waves, investigating refraction in glass blocks, the groups of the electromagnetic spectrum, the continuous spectrum, and what our eyes can detect, absorption, transmission and the velocity of electromagnetic waves, emitting and absorbing thermal radiation, constant temperature and the temperature of the Earth, how radiation is generated, and why danger rises with frequency, harmful effects of excessive exposure to radiation and uses of electromagnetic radiation.
Sample questions from Light and the Electromagnetic Spectrum
Answer each one closed book first, then open the answer.
-
Reflection, refraction and total internal reflection
Define total internal reflection.
Show the answer
Total internal reflection is when light meeting a boundary from inside the denser material is entirely reflected back and none escapes. -
Why objects appear coloured
State the colour a white shirt appears when it is lit only by red light.
Show the answer
It appears red, because red is the only colour available for it to reflect. -
Properties of electromagnetic waves
Explain why light from a distant star reaches the Earth across empty space but the star's sound cannot.
Show the answer
Light is an electromagnetic wave that travels through a vacuum, while sound needs particles to carry it. -
Investigating refraction in glass blocks
Give one source of error when refraction in a glass block is investigated, and how it can be reduced.
Show the answer
The beam from a ray box is wide, so fit a narrow slit and always mark the centre of the ray. -
The continuous spectrum, and what our eyes can detect
Compare the frequency of ultraviolet with the frequency of infrared.
Show the answer
Ultraviolet has the higher frequency, because it lies nearer the gamma ray end of the spectrum. -
Absorption, transmission and the velocity of electromagnetic waves
Explain why a substance that slows light more also bends it more at the same angle of incidence.
Show the answer
The greater the difference in speed across the boundary, the more the wavefront pivots and the more the ray turns. -
Constant temperature and the temperature of the Earth
State what happens to a body that absorbs more average power than it radiates.
Show the answer
Its temperature rises. -
How radiation is generated, and why danger rises with frequency
Describe what can happen to an atom that absorbs electromagnetic radiation.
Show the answer
It can be raised to a higher energy state, and with enough energy an electron may be removed from it altogether.
The 13 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Reflection, refraction and total internal reflection | The law of reflection and the normal, refraction through a glass block, total internal reflection, its two conditions and the critical angle, optical fibres, and specular and diffuse reflection from mirrors, paper and wet roads. | 17 |
| Why objects appear coloured | Why objects look red, white or black in white light, what a colour filter transmits and absorbs, and how books, shirts and cars appear when seen through filters or lit by coloured light. | 8 |
| Lenses, ray diagrams and images | Focal length and lens power, how shape affects power, the principal focus, how converging and diverging lenses refract rays, rays through the centre and the focus, and the real and virtual images each lens forms. | 20 |
| Properties of electromagnetic waves | Electromagnetic waves as transverse waves travelling at 3.0 × 10⁸ m/s through a vacuum, why they form one family, and the energy they transfer from source to absorber in sunlight, microwave ovens and radio aerials. | 12 |
| Investigating refraction in glass blocks | Drawing round the block, marking the ray with crosses, measuring the angles of incidence and refraction from the normal, the variables involved, and the pattern of results. | 12 |
| The groups of the electromagnetic spectrum | The seven groups of the electromagnetic spectrum in order of wavelength, which groups lie at each end and between their neighbours, and the colours of the visible spectrum from red to violet. | 10 |
| The continuous spectrum, and what our eyes can detect | Why the spectrum is continuous, how frequency and wavelength change from radio waves to gamma rays, and the narrow band of visible light the eye detects, with infrared and ultraviolet just outside it. | 13 |
| Absorption, transmission and the velocity of electromagnetic waves | How absorption and transmission depend on wavelength in glass, oven doors, bone, black surfaces and the atmosphere, light slowing and refracting in glass and water, prisms splitting white light, and how radio waves are produced and received by an aerial. | 18 |
| Emitting and absorbing thermal radiation | How the intensity and wavelength of radiation change as a body gets hotter, infrared from everyday objects, the Sun and the Earth, and investigating emission and absorption by surfaces with a Leslie cube, a radiant heater and covered beakers. | 28 |
| Constant temperature and the temperature of the Earth | Radiating and absorbing the same average power at a constant temperature, why bodies warm, cool or settle, cooling on a clear night, and how reflection, absorption and greenhouse gases set the temperature of the Earth. | 17 |
| How radiation is generated, and why danger rises with frequency | Why danger rises with frequency across the electromagnetic spectrum, ranking groups by potential harm, radiation from changes in electrons and nuclei, atoms raised to higher energy states or ionised, sodium lamps, and the sources of X-rays and gamma rays. | 12 |
| Harmful effects of excessive exposure to radiation | Harmful effects of excessive exposure to microwaves, infrared, ultraviolet, X-rays and gamma rays, from internal heating and skin burns to skin cancer, eye damage and cell mutation, with sunbathing, radiographers and sunglasses as examples. | 8 |
| Uses of electromagnetic radiation | Uses of radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays, from broadcasting, satellite links, cooking and thermal imaging to optical fibres, security marking, disinfecting water, medical images, sterilising and cancer treatment. | 19 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
-
Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
-
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
-
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
Edexcel GCSE Physics, Higher tier Active Recall Guide
Every topic, not just this one. 2,063 questions with their answers.