Chapter 6 - Electromagnetic Waves Flashcards
What wave has the longest wavelength and lowest frequency
Radio waves
What is the link between the frequency of an electromagnetic wave and the energy it transfers
The higher the frequency of an electromagnetic wave, the more energy it transfers
What happens the shorter the wavelengths
The more information the waves carry
What are optical fibres used for
To transmit signals carried by visible light or infrared radiation. The signals travel down the fibre by repeated total internal reflection
Why are optical fibres useful in communication
They carry much more information and are more secure than radio wave or microwave transmissions
What is the Doppler effect
The wavelength and frequency of the waves detected by the observer changing from the original produced by the source
What happens when the source moves away from the observer
The observer wavelength increase and the frequency decreases
What happens when the source moves towards the observer
The observers wavelength decreases and the frequency increases
What does red shift mean
The frequency has decreased and the wavelength has increased. It is evidence that the universe is expanding.
What does blue shift mean
A galaxy is moving towards us.
What happens the further away the Galaxy
The bigger the red shift. This suggests that distant galaxies are moving away from us and the most distant galaxies are moving the fastest.
What is the Big Bang theory
A massive explosion that started at a very small initial point.
If the universe behind with a Big Bang, what would have been produced
High energy gamma radiation would have been produced. As universe expanded, this would have become lower energy radiation
What is the radiation produced by the Big Bang
(CMBR) cosmic microwave background radiation
What wave has the shortest wavelength and highest frequency
Gamma rays
