Radio waves

how do we generate radiowaves?

1. use a transmiter connected to an oscilloscope to see the frequency of the AC we're using because the oscilloscope allows us to see this on the screen ( which is important because the frequency of the AC determines the type of wave we're going to produce)

2. we then detect the radiowave using a receiver which absorbs the energy and generates another AC which it displays on another oscilloscope

3. the frequency of this AC current it produces is the same as the frequency we used to generate the radiowave in the first place

what is the main use for radiowaves

communication

what are the three types of radiowaves

long waves, short waves and very short waves

what are long waves used for

long waves can be transmitted long distances ( eg. UK to Singapore) without having to interact with anything along the way. This is because they can diffract (bend) around the curved surface of the earth

what are short waves used for

short waves can also be transmitted long distances however they can't curve around the earth. So instead they're reflected from the ionosphere (electrically charged layer of the upper atmosphere) so they're mainly used for things such as bluetooth

what are very short waves used for

TV and FM radios ; these ones have to travel directly from the transmitter to your receiver, which is why you don't always get a great radio signal in the car because surrounding structures like tunnels can get in the way