Electromagnetic Waves Flashcards
How are gamma waves produces
changes in the nucleus of an atom
e.g. radioactive decay
what is refraction
waves change speed and direction as they cross the boundary from one substance to another due to change in velocity
why are x-rays used in medical imaging
they pass through flesh but not bone
which electromagnetic waves are harmful to human body by causing cancer
-ultraviolet
-x-rays
-gamma
uses of infrared radiation
-heating
-remote controls
-infrared cameras
-cooking food
uses of microwaves
-satellite communications
-cooking food
uses of radio waves
-television
-mobile phones
-bluetooth signals
how are radio waves detected
waves absorbed and create an alternating current with the same frequency as the radio wave
how are radio waves produced
oscillations in an electrical circuit
how can electromagnetic waves be produced
changes inside an atom/nucleus
list all of the types of electromagnetic wave in order of decreasing wavelength (increasing frequency)
radio, microwave, infrared, visible, ultraviolet, x-rays, gamma
explain why electromagnetic waves aren’t mechanical
they can travel through a vacuum (doesn’t need substance to travel)
are electromagnetic waves longitudinal or transverse
transverse
what happens to the direction of refracted electromagnetic wave when it slows down as it crosses the boundary from one substance to another
bends towards the normal
