Waves Flashcards
List 3 properties of the waves in the EM spectrum?
All can travel through a vacuum
All are transverse waves
All will transfer energy
All travel at the speed of light
What are the types of EM Wave? In order of Wavelength.
Radio Micro Infrared Visible Ultraviolet X-Ray Gamma
What is the difference between Analogue and Digital signals?
Analogue can be any value whereas digital is discreet- it can only be 2 values, off and on.
Give an example of analogue and an example of digital signals.
Analogue- LP/Vinyl records
Digital- CDs
List a danger and use for Radio waves
Communication, radio and broadcasting.
Probably no dangers.
List a danger and use for Microwaves?
Satellite communication and cooking.
Internal heating of body tissue.
List a danger and use for Infared?
Radiant heaters, grills and remote controls.
Causes burning of tissues
List a danger and use for visible light waves?
Seeing, optic fibres and photography.
Very bright light and damages eyes.
List a danger and use for ultraviolet?
Fluorescent tubes and security marking.
Blindness and can damage surface cells.
List a danger and use for X-rays?
Imaging internal body structures and atomic structure.
Long term exposure can cause cancer.
What is noise? (In terms of analogue and digital signals)
When signals are sent they become noises, this is when the signal becomes distorted.
Digitalis signals can be cleaned much more easily because ons and offs are very clear.
List the three ways wave direction can be changed?
Refraction- wave bends moving between mediums.
Diffraction-
Reflection-
What is the law of reflection?
It states that the angle of incidence is = to the angle of reflection
How do you work out:
A) angle of incidence
B) angle of refraction?
i= N=sin i/sin r i= sin-1(n x sin r)
r= N= sin i/sin r r= sin-1 (sin i/n)
Which way does light bend between mediums?
When entering a medium with a higher n light bends towards the normal and visa versa.
