Electromagnetic spectrum Flashcards
what are electromagnetic waves
transverse waves that transfer energy from the source of waves to an absorber
EM spectrum in order of increasing frequency and decreasing wavelength
Radiowaves, Microwaves, Infrared radiation, Visible light, Ultraviolet light, X rays, Gamma Rays
what part of the EM spectrum can humans detect
only visible light
what are the two components of an electromagnetic wave
oscillating and magnetic fields
EM waves through a vacuum
EM waves form a continuous spectrum and all types of EM waves travel at the same velocity thtough a vacuum
Radio waves uses
Telecommunication, TV and radio
dangers of radio waves
does not cause any damage if absorbed by the human body, can be reflected or refracted to change their direction
uses of microwaves
Cooking and satellite communications
dangers of microwaves
Heating body tissues, cataracts, skin burns
uses of infrared radiation
cooking, night vision, tv remote, burglar alarms
dangers of infrared radiation
can cause skin burns
visible light uses
seeing
dangers of visible light
Usually harmless however some light can be so intense and harm receptor cells in eyes
uses of ultraviolet light
detects counterfeit notes
dangers of UV light
sunburn and skin cancer
uses of x rays
medical imagery
dangers of x rays
increased risk of cancer
uses of gamma rays
killing cancer cells and bacteria
dangers of gamma rays
skin cancer, cause ionisations
how is refraction caused
difference in velocity of waves in different substances
how can an electric signal be produced
oscillating electric charge in radio transmitter produces EM wave. when wave reaches a radio aerial, the process is reversed and the oscillating waves generate an electric signal
how can radio waves induce oscillations in an electrical circuit
when radio waves are absorbed, they can create an alternating current with the same frequency as the wave, inducing the oscillations
how are gamma rays produced
changes in the nucleus of an atom
what dangers do x rays and gamma rays both have
ionising radiation which can cause the mutation of genes and cancer.
