Section 3 Flashcards
What does diffracted mean?
Bend round edges and through gaps, causing the waves to spread out.
When do waves diffract?
When they pass through a gap or past the edge of an object.
What does the amount of diffraction depend on?
The size of the gap relative to the wavelength.
What happens when the gap is much wider than wavelength?
Little diffraction.
What happens when the gap is a bit wider than wavelength?
Diffraction only occurs at edges.
What happens if the gap is the same as the wavelength?
Maximum diffraction.
What affects how much a wave diffracts by?
The longer the wave, the more they diffract and bend around.
What does information have to be converted to before it is transmitted over long distances?
Electrical signals.
What happens to these electrical signals?
They can be sent down telephone wires or carried on EM waves.
What can signals be?
Analogue or digital.
What is analogue signal?
Signal that can take any value with a certain range.
What is the amplitude and frequency of analogue waves?
They can vary continuously.
What are digital signals?
They can only take two values.
What do signals do as they travel?
They weaken.
What needs to be done to signals along their route?
They need to be amplified.
