Microwaves
Physics: Edexcel IGCSE, topic 3.3.7
Microwaves
Microwaves are the 6th type of wave in the electromagnetic spectrum.
Uses
- Microwaves are used for the purpose of satellite communications (transmitting signals between stations on Earth and satellites).
- Microwaves are also used to transmit signal from a nearby phone mast (transmitter) to a mobile phone.
- Microwaves are absorbed by water, heating up the water in the process. This makes microwaves useful for cooking food because food contains lots of water.
Risks
- Because humans are largely made up of water, exposure to microwaves could have a harmful effect.
Safety
- We should always reduce any exposure to microwaves.
- As with X-rays, always have some sort of shielding between the source of microwaves and living tissue.
- An example of this is the protective shielding on microwave ovens.
Explanation
- Microwaves have a high enough frequency to penetrate the Earth’s atmosphere and to reach satellites.
- Microwaves travel in straight lines through the atmosphere. This makes them good for transmitting (sending) signals.
Test yourself on Microwaves
What is an example of a safety measure used when dealing with microwaves?
Microwaves transfer energy to water molecules and can cause severe burns. How are microwave ovens safe to use?