4174307
Description
Flashcards by Bronagh Tea, updated more than 1 year ago
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Created by Bronagh Tea
almost 9 years ago
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| Question | Answer |
| What are the properties of light? | 1. light moves in straight lines 2. light travels very fast 3. light travels much faster than sound (eg thunder and lightening) 4. light travels faster in air than any other material. |
| What is the law of reflection? | The angle of incidence is always equal to the angle of reflection |
| What happens when fraction occurs? | -some light is refracted internally - when light slows down it bends towards the normal. - when light speeds up it bends away from the normal. |
| How fast are each of the colours in the dispersion of light? ROYGBIV | -White light is all the same speed - Red light is the fastest as it refracts the least - Violet light is the slowest as it refracts the most |
| What are the two types of lenses? | Convex () and concave )( |
| What is the principal focus? | Rays of light parallel to the principal axis of a convex lens all converge at the same point, lying on the principal axis |
| What is the focal length? | the distance between the principal focus and the optical centre lens. |
| What is the location of the image at each of the object points? | -On the same side as the lens but further from the lens -at infinity -Beyond 2F -at 2F -Between F and 2F -At F |
| What is the nature of each and are each of them erect or inverted? | - Virtual -Erect - Real -virtual - Real -virtual - Real -virtual - Real -virtual - Real -virtual |
| What size are each of them? | - larger - larger - Larger - same size - Smaller - smaller |
| What are the uses for each? msctca | - magnifying glass - search light - camera projector - Telescope - Camera - Astronomical telescope |
| what is a diffuse reaction? | When the light is scattered in different directions. Eg A car head light or a periscope |
| What is total internal reflection? | as the angle of incidence increases, the refracted ray becomes weaker, the internally reflected ray becomes stronger critical angle is around 42' until a weak refracted ray is observed with a large angle of refraction. In angles of incidence above the critical angle there is no fraction all totally internally reflected. |
| What are the us for total internal refraction? | Binoculars, periscopes, optical fibres and Endoscopes |
| what are optical fibres? | Lengths of solid glass with outer cladding and protective plastic sheet. |
| How do optical fibres work? | Light strikes the core-cladding boundary at an angle greater than the critical angle and is totally internally reflected at the surface of the glass core. |
| What are optical fibres used for? | to transmit telephone endoscopes and video signals. |
| What are the advantages of optical fibres? | They can carry much more information than copper cables can of the same diameter. |
| What happens if the optical fibre is too tightly bent? | The angle of incidence core may become less than the critical angle and the light will be lost by refraction into the cladding. |
| What are uses for each of the electromagnetic waves? Remember my instructions visible under x-ray goggles | 1. entertainment and emergency services 2. mobile phones and microwaves 3. toasters and ovens 4. human vision, photosynthesis 5. tanning beds, bank notes 6. detect broken bones and tumours 7. destroy viruses and kill cancer cells |
| What are the dangers for each of the electromagnetic waves? | 1. - 2. eye cataracts 3. damages cells by burning 4. snow blindness 5. skin cancer 6. and 7. cause cancer and disrupt DNA |
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