What do we attach to an oscilloscope to generate a radio wave
A transmitter
what is an oscilloscope
a device used to display the wavelength, amplitude, and frequency of voltage or current
how do X-rays and gamma rays compare to other electromagnetic waves, in terms of wavelength and frequency
x rays and gamma rays the shortest wavelengths and highest frequencies of all the electromagnetic waves
how can ultraviolet radiation be harmful
it can ioniseatoms inside our cells, causing damage; this can lead to sunburn, and in some cases can lead to cancer
can the microwaves used in satellite communications be absorbed by water molecules, explain
no, if they were absorbed by water molecules they wouldn’t be able to pass through the atmosphere
what is the key property of a transverse wave?
transverse waves oscillate perpendicular to the direction of energy transfer
do radio waves have a high or low wavelength and frequency
high wavelength, low frequency
how do microwave ovens work
the microwaves are absorbed by the water molecules in the food or object being heated; this transfers energy to them, which can then be transferred throughout the food or object to heat it
which 2 types of electromagnetic waves can be used in communications
radio waves, microwaves and sometimes infrared radiation
give 3 uses of gamma rays in hospitals
to sterilise equipment, in medical imaging (e.g. radioactive tracers) and to treat cancer
what are the 7 colours of visible light, starting with the longest wavelength
the acronym ROYGBIV can be used to remember the order of wavelengths in visible light, from longest to shortest wavelength: (longest) red, orange, yellow, green, blue, indigo, violet (shortest)
do X-rays or gamma waves have higher frequency
gamma waves have higher frequency
give 4 uses of ultraviolet radiation
fluorescent lights, checking for ‘invisible’ markings in things like passports, destroying microorganisms to sterilise water and tanning beds to get a suntan
how do radio waves generate a current
when radio waves are absorbed, they may create an alternating current with the same frequency as the radio wave itself, so radio waves can themselves induce oscillations in an electrical circuit
are electromagnetic wavestransverse or longitudinal
electromagnet waves are transverse
are radio waves generated using alternating or direct current
alternating current
what do we attach to an oscilloscope to receive a radio wave
a receiver
what are the 7 types of waves in the electromagnetic spectrum, starting with the longest
radio waves, microwaves, infrared, visible light, ultra violet, X-rays and gamma rays
does visible light or ultraviolet radiation have longer wavelengths
visible light has longer wavelengths
what precautions do hospital staff take against the harmful effects of x rays
they leave the room when the x rays are taken and they wear lead vests which stop the x rays
which 2 types of electromagnetic waves are considered ionising
gamma rays, x rays and some types of ultraviolet radiation
which type of electromagnetic wave has the highest energy
gamma rays
which type of electromagnetic wave has the highest frequency
gamma rays
does microwave or infrared radiation have longer wavelengths
microwaves have longer wavelengths than infrared waves
outline how x ray machines at the hospital work
X rays are fired at the patient; x rays are absorbed by materials which are very dense, like bones; x rays are transmitted through materials which are not very dense, like lungs and intestines; the x rays that pass through are detected by a detector plate, forming an x ray image
give 3 uses of radio waves
television transmission, radio transmission and Bluetooth
what is fluorescence
fluorescence is the phenomenon of ultraviolet light energy being absorbed and then re-emitted as visible light
what are x ray machines at the hospital used for
x rays are used to view the internal structures of our bodies, to help diagnose illness
how fast do electromagnetic waves travel when in a vacuum
3x10 power of 8 m/s
give 3 uses of infrared radiation
in infrared cameras to detect motion or monitor temperature, to heat food in a toaster or grill and to what a room via an electric radiator
what is the key feature of visible light
our eyes are able to detect those wavelengths of electromagnetic radiation, which allows us to see
what is infrared radiation emitted from
infrared radiation is emitted from all objects that have thermal energy; the hotter an object is, the more infrared radiation it will emit