Flashcards
Cooking and communicating waves
Cards in this deck (22)
- 1Which type of radiation does not penetrate food very easily?Infrared radiation does not penetrate food very easily.
- 2Which type of wave penetrate up to 1cm of food?Microwaves penetrate up to 1cm into food.
- 3Microwaves can penetrate glass or plastic but are reflected by what?Microwaves can penetrate glass or plastic but are reflects by shiny metal surfaces.
- 4Fill the gaps: - Special glass in a ......... oven door ........ microwaves. - They can cause .... tissue to .....- Special glass in a microwave oven door reflects microwaves.
- They can cause body tissue to burn. - 5How is energy transferred?Energy is transferred by waves.
- 6What does the amount of energy depend on?The amount of energy depends on the frequency or wavelength of the wave.
- 7True or False? High frequency (short wavelength) waves transfer more energy.True.
High frequency waves transfer more energy. - 8How do normal ovens cook food?Normal ovens cook food by infrared radiation.
- 9How do normal ovens cook food by infrared radiation?Normal ovens cook food by infrared radiation:
- energy is absorbed by the surface of the food
- the kinetic energy of the surface food particles increases
- the rest of the food is heated by conduction - 10How do microwave ovens cook food?Microwave ovens cook food by microwave radiation.
- 11How do microwave ovens cook food by microwave radiation?Microwave ovens cook food by microwave radiation:
- the water or fat molecules in the outer layers of food vibrate more - 12Fill in the gaps: Microwaves have wavelengths between ... and .....Microwaves have wavelengths between 1mm and 30cm.
- 13True or False? Mobile phones use longer wavelengths than microwave ovens. - Less energy is transferred by mobile phones.True.
Mobile phones use longer wavelengths than microwave ovens.
- Less energy is used by mobile phones. - 14What can microwave radiation be used for?Microwave radiation can be used to communicate over long distances.
- 15What must the transmitter and receiver be?The transmitter and receiver must be in line of sight.
- 16Where are aerials normally situated?Aerials are normally situated on the top of high buildings.
- 17What are satellites used for?Satellites are used for microwave communication.
- 18How are satellites used for microwave communication?Satellites are used for microwave communication.
- The signal from Earth is received, amplified and re-transmitted back to Earth.
- Satellites are in line of sight because there are no obstructions in space.
- Large aerials can handle thousands of phone calls and television channels at once. - 19Fill the gaps: There are ........ about the use of ...... phones and where phone ..... are situated.There are concerns about mobile phones and where phone masts are situated.
- 20Why do scientists publish their studies?Scientists publish their studies to allow others to check their findings.
- 21Signal strength for mobile phones can change a lot over a short distance. Suggest three reasons as to how these changes can occur.Signal strength for mobile phones can change a lot over a short distance.
- Microwaves do not show much diffraction.
- Adverse weather and large areas of water can scatter the signals.
- The curvature of the Earth limits the line of sight so transmitters have to be on tall buildings or close together. - 22Why are mobile phones banned on planes and in many hospitals?Mobiles phones can interfere with sensitive equipment:
- They are banned on planes and in many hospitals.
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- GCSE Science Year 10 Flashcards on Cooking and communicating waves, created by annjb2898 on 18/05/2014.
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