P1c-a Spectrum Of Waves Flashcards
What is frequency?
The number of complete wave cycles or oscillations?
How do all electromagnetic waves travel in space or a vacuum?
At the same high speed
What are the main features of a transverse wave?
Trough and crest
Amplitude
Wavelength
What is a wavelength?
The length of a full cycle of the wave
How do electromagnetic waves travel through a particular medium?
In straight lines
What does refraction involve?
A change in direction of a wave due to the wave passing from one medium into another
What happens if a wave meets a new medium at an an angle?
Its refracted
What is diffraction?
Waves spreading out
What happens to diffraction when the gap is much wider than the wavelength?
Little diffraction
What happens to the diffraction when the gap is a bit wider than wavelength?
Diffraction only at edges
What happens to diffraction when the gap is the same as the wavelength?
Maximum diffraction
What are the seven types of electromagnetic waves in order of increasing frequency and decreasing wavelength?
Radiowaves Microwaves Infrared radiation Visible light Ultra violet X rays Gamma rays
How can radio waves with long wavelengths be received across the world?
The diffract around the curved surfaces of the world because they are large compared to obstacles
Why can’t short wave radio signals travel far?
They don’t diffract very much
Short wave signals are reflected off the ionosphere so tv/radio signals must be in line of sight
Why do bigger telescopes give us better resolution?
They cause less diffraction
Big receiver
Less diffraction- clearer information
Why is it hard to get good resolution on optical microscopes?
Small size
Get some diffraction
