click below
click below
Normal Size Small Size show me how
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 |