Cards (33)

  • 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 ionise atoms 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 waves transverse 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
  • give 2 uses of visible light
    cameras and optical fibres