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CP5F
GCSE Combined Science Physics
Question | Answer |
---|---|
1What are ray diagrams. | Ray diagrams are ways of modelling what happens during reflection and refraction. |
2 What is a normal? | A line drawn at 90° to the interface or the mirror. |
3 From where are angles of incidence, angles of reflection and angles of refraction measured? | They are measured from the normal |
4 State the Law of Reflection | The angle of incident is equal to the angle of refraction. |
5 Does light travel faster in air or in water and give the reason | Light travels faster in air than in water. This is due to water having a greater density than air. |
6 What is refraction? | The bending of light rays as they go from one medium to another medium across an interface. |
7 What are the two changes that occur when a ray is refracted at an interface? | There is a change in speed and a change in direction. |
8 What happens when a ray of light is incident at 90° to the interface? | The direction remains the same and the speed changes |
9 What happens when a ray of light is incident an angle other than 90°. | Both the speed and the direction changes |
1.Two examples of electromagnetic waves | Any two: Radio wave, microwave ,infrared, visible light, ultra violet x rays and Gamma rays |
2. State one thing all electromagnetic waves have in common. | They are all transverse |
3. State another thing all electromagnetic waves have in common. | They all travel at the speed of light in a vacuum. |
4.Which electromagnetic wave has frequencies a little higher than visible light | Ultra violet radiation |
5.Which electromagnetic wave has frequencies a little lower than visible light | Infrared radiation |
6.Define what is a wavelength | The distance between the samepoint on 2 succesive waves |
7.Define what is frequency | The number of cycles per second |
8. Who discovered infrared radiation? | |
9. Which type of electromagnetic radiation does all objects emit? | Infrared radiation |
10. How is the temperature of a body related to its energy? | The higher the temperature the greater the energy |
11. How are pit viper snakes able to see their prey in the dark? | They have an organ under their eye that detect infrared radiation |
12. What is a vacuum? | A region where no matter is present. |
1.What are the main grouping of the electromagnetic spectrum | Radio wave, microwave, infrared, Visible light, ultraviolet, X rays and gamma rays |
2. Which electromagnetic wave can be detected by the naked eye? | Visible light |
3. What characteristics are used to group electromagnetic waves? | Wavelength or frequencies |
4. Which electromagnetic wave has the greatest frequency | Gamma rays |
5. Which electromagnetic wave has the greatest wavelength? | Radio waves |
6. Which electromagnetic wave has the most energy? | Gamma rays |
7. What is always present with infrared radiation | Heat |
8. State the order of the colours in the visible spectrum. | Red, Orange, Yellow, Green, Blue, Indigo and Violet |
1. Which 2 EM waves can be sent through light fibres? | Visible light and infrared radiation |
2. State two other use of infrared radiation | Cooking(grills and toasters), remote controls |
3. Where are microwaves used for communication? | In Cell Phones |
4. Where are microwaves used for its energy | In Microwave ovens |
5.State two ways radio waves are used | Radio broadcasts and satellites |
6. Why can radio waves from a source be detected on the other side of the globe and microwaves cannot be detected on the other side of the globe. | At an appropriate angle radio waves can be refracted by the ionosphere whereas microwaves pass straight through the ionosphere. |
7. How are radio waves produced? | By vibrations in electrical circuits |
8. How are radio waves detected? | Radio waves are absorbed by metals which oscillates and cause vibrations in the circuits connected to aerials |
9. Which two parts of the electromagnetic spectrum are used for cooking? | Microwave and infrared |
10. Which 3 parts of the electromagnetic spectrum are used for communication? | Radio waves, Microwave and infrared |
1. State 2 uses of ultraviolet radiation. | Detect fake bank notes and sterilise water |
2. What is fluorescence? | When a material absorbs Ultra violet radiation and re emits it as visible light |
3. Why are x rays able to produce an image on a screen? | X ray passes through flesh but are absorbed by the bones |
4. Suggest another use of X ray. | Airport security scanners |
5. State 3 uses of gamma rays. | Sterilise medical equipment, Preserve food and to detect and treat cancer |
6. Describe the different ways in which gamma rays and x rays pass through muscle, fat and bones. | Gamma rays pass through fat, muscle and bones while X rays can pass through fat and muscle but not bones. |
7. Why are surgical equipment placed in plastic bags before sterilisation. | To prevent the equipment for becoming contaminated before use. |
8. List the electromagnetic waves in order of decreasing frequency. | Gamma rays, x rays, ultra violet, visible light, infrared, microwave and radio waves. |
1. What is the difference between the microwaves used in our mobile phones and those used in the microwave oven? | The microwaves used in mobile phones is the lower frequency end of the Microwave while the microwaves used in the microwave oven is the higher frequency end of the Microwave |
2. State 2 dangers of Infrared radiation. | Burn on the skin and damage to cell from over exposure |
3. State 2 ways of protecting our skin from sunlight. | Staying out of the strongest sunlight and wearing sun cream with high skin protection factor |
4. State two dangers of ultraviolet radiation. | Sun burn and skin cancer |
5. How does excessive exposure to x rays and gamma rays affect the human cells? | Can lead to mutation of cells |
6. Electromagnetic radiations are produced by changes in the --------------- or the -------------. | The electron or the nuclei. |
7. How is the danger linked to an electromagnetic wave associated with its frequency? | The higher the frequency of the electromagnetic radiation the greater the danger associated with that electromagnetic radiation. |
8. Why could the microwaves with frequencies fit for use in a microwave oven be harmful to humans? | Microwaves with that frequency are able to boil water and our body is mostly water so it could heat cells inside our body. |
What is the speed of elecrtomagnetic radiation? | 300 000 000 m/s |
What is the EM radiation with the shortest wavelength? | gamma |
What is the EM radiation with the longest wavelength? | Radio |
What is the EM radiation with the highest frequency? | Gamma |
What is the EM radiation with the lowest frequency? | Radio |
List the EM spectrum from long to short wavelength. | Radio, microwave, infrared, visible, UV, X-rays, gamma |
Can EM waves travel through space? | yes |
Can sound waves travel through space? | no |
Does a sound wave travel faster in water or air? | water |
Name a use of radio waves | TV and radio transmission |
What EM wave is used for satellite communication? | microwave |
Give one use of microwaves | cooking food |
Give two uses of IR radiation | electrical heaters, infrared cameras |
Give a use of visible radiation | Fibre optic communications |
Which radiation is used in sun tanning? | UV |
Give one use of X-rays. | Medical imaging |
Give one use of gamma rays | Medical treatments |
Why are X-rays good for taking images of bone? | absorbed by bone but transmitted through soft tissue |
Why are gamma rays used in medical treatment? | Can kill cancer cells |
What are the risks of exposure to UV radiation? | Premature skin aging, increased risk of skin cancer |
What are the risks of exposure of X-rays? | X-rays are ionising so can cause mutations which may result in cancer |
What are the risks of exposure to gamma rays? | Gamma rays are ionising so can cause mutations which may result in cancer |