Flashcards
Light and lasers
Flashcards do conjunto (20)
- 1What does Morse code use to represent letters of the alphabet?Morse code uses a series of dots and dashes to represent letter of the alphabet.
- 2Fill in the gaps: This code is used by signalling lamps as a series of short and long ....... .. ......This code is used by signalling lamps as a series of short and long flashes of light.
- 3Finish the sentence: When a signal is sent by light, electricity, microwaves or radio, it is almost ..............When a signal is sent by light, electricity, microwaves or radio, it is almost instantaneous.
- 4Each method of transmission has advantages and disadvantages. Name what these could be.- Can the signal be seen by others?
- Can wires be cut?
- How far does the signal have to travel? - 5What is white light made up of?White light is made up of different colours of different frequencies out of phase.
- 6Name the three features about laser light.Laser light has only a single frequency, is in phase and has a low divergence.
- 7Laser light is used to do what?Laser light is used to read from the surface of a compact disc (CD).
- 8How does this work?- The surface of the CD is pitted
- The pits represent the digital signal
- Laser light is shone onto the CD surface and the difference in the reflection provides the information for the digital signal. - 9What normally happens when light travels from one material to another.When light travels from one material to another, it is normally refracted.
- 10If it is passing from a more dense material into a less dense material, is the angle of refraction larger or smaller than the angle of incidence?If it is passing from a more dense material into a less dense material, the angle of refraction is larger than the angle of incidence.
- 11Draw a labelled diagram to show what happens when light exits a glass block.
- 12What is the angle of incidence called when the angle of refraction is 90°?When the angle of refraction is 90°, the angle of incidence is called the critical angle.
- 13Draw a labelled diagram to show what happens when the angle of incidence is at the critical angle.
- 14If the angle of incidence is bigger than the critical angle, the light is reflected. What is this called?If the angle is bigger than the critical angle, the light is reflected. This is total internal reflection.
- 15Draw a labelled diagram to show total internal reflection.
- 16What are telephone communications and computer data are transmitted long distances along?Telephone communications and computer data are transmitted long distances along optical fibres.
At the speed of light
- 200000 km/s in glass - 17Fill the gaps: Some ...... are coated to improve ...........Some fibres are coated to improve reflection.
- 18What is an optical fibre?An optical fibre is a flexible optically transparent fibre, usually made of glass or plastic, through which light passes by successive internal reflections.
- 19What is an endoscope and what does it allow doctors to do?An endoscope is a device using optical fibres which allows doctors to look inside the human body.
- 20How does an endoscope work?- Light passes along one set of optical fibres to illuminate the inside of the body.
- The light is reflected.
- The reflected light passes up another set of fibres to an eyepiece or camera.
Informações
- Descrição
- GCSE Science Year 10 FlashCards sobre Light and lasers, criado por annjb2898 em 18-05-2014.
- Criado por
- annjb2898 · mai 2014
- Atualizado
- 19 mai 2016
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