Topic 6 Tadio Waves Flashcards
What are radio waves made by
Oscillating charges
What are EN waves made up of
Oscillating electric and magnetic fields
What are alternating currents made up of
Oscillating charges
What is the charge is oscillate what do they produce
Oscillating electric and magnetic field e.g. electromagnetic waves
What is the frequency of the waves produced equal to
The frequency of the alternating current
What is the object called which charges oscillate to create radio waves
Transmitter
What happens when transmitted radio waves reach the receiver
The radio waves are absorbed
What is the energy carried by the waves transfer to
Electrons in the material of the receiver
What does the energy cause the elections to do
Oscillate and if the receiver is part of a complete electrical circuit it generates an alternating current
What is the current have
The same frequency is the radio waves that generated it
How long are radio waves wavelength
10 cm
How far can longwave radio wavelength be
1-10 km
What can longwave radio wavelengths be used for
Transmit signals halfway around the world
Why can longwave radio length be able to talk around the world
Cause long wavelength diffracts around curve surfaces and can also diffract around hills and into tunnels
How long are short wave radio signals
10 m to 100 m
