Radiowaves Flashcards
1
Q
What are the characteristics of a radio wave
A
- Radiowaves are part of the electromagnetic (EM) spectrum
- They are used for communication
- They have the longest wavelength and the shortes frequency out of the EM spectrum
2
Q
What are waves belonging to the EM spectrum
A
- Waves that are made up of oscillating electric and magnetic fields
3
Q
How can we generate waves from the EM spectrum and why does it work
A
- We can use electricity to generate waves from the EM spectrum as they are made up of oscillating electric and magnetic fields
- We can use an alternating current to do so as it is made up of oscillating charges
4
Q
How do we send and receive radiowaves
A
- Oscilliscope (generates wave) = allows us to see the frequency of the alternating current. The frequency of the AC determines the frequency of the wave
- Transmitter (sends the wave)
- Receiver (receives the wave) = absorbs energy and generates another AC of matching frequency
- Oscilliscope (displays AC matching frequency of the wave)
5
Q
Why can we use radiowaves to transmit information
A
- As both transmitted and received wave have the same frequency, we can send and receive information
6
Q
What is the ionosphere
A
- Electrically charged layer of the upper atmosphere
7
Q
What is a very short wave (radiowaves)
A
- Used in TVs and radio’s
- Information is sent directly from transmitter to receiver
- Buildings and other structures can cause interference and cause disturbance
8
Q
How are radiowaves used for communication?
A
- Wave is reflected back and forth from the ionosphere of the Earth