Waves

• Sketch and label a transverse wave

  
• Sketch and label a longitudinal wave

  
• Define a tranverse wave

  The vibrations/oscillations of the waves are perpendicular to the direction of energy transfer
• Define a longitudinal wave

  The vibrations/oscillations of the waves are parallel to the direction of energy transfer
• Define amplitude

  the maximum displacement of a point on a wave away from its undisturbed position
• Define wavelength

  the distance from a point on one wave to the equivalent point on the next wave
• What is equation linking time period and frequency?

  Time period = 1 ÷ frequency
• What are the units for time period?

  s or seconds
• What are the units for frequency?

  Hz or Hertz
• What is equation linking wave speed, frequency and wavelength?

  wave speed = frequency × wavelength
• What are the units for wavelength?


  m or metres
• What are the units for wave speed?

  m/s
• What is order of the electromagnetic waves from highest frequency to lowest frequency?

  • Gamma
  • X-Rays
  • UltraViolet
  • Visible light
  • Infrared
  • Microwaves
  • Radiowaves
• What can radio-waves be used for?


  television and radio
• What can microwaves be used for?

  • satellite communications
  • cooking food
• What can infrared be used for?

  • electrical heaters
  • cooking food
  • infrared cameras
• What can visible light be used for?

  fibre optic communications
• What can ultraviolet be used for?

  • energy efficient lamps
  • sun tanning
• What can gamma rays be used for?

  • Sterilising equipment
  • medical treatment
• What can x-rays be used for?

  • medical imaging
  • treatments
• What is Radiation dose?

  " a measure of the risk of harm resulting from an exposure of the body to the radiation."
• What is 1000 millisieverts (mSv) equivalent to in sieverts?

  1 sievert
• What are the dangers of ultraviolet waves?

  • Can cause skin to age prematurely
  • increase the risk of skin cancer
• What are the dangers of X-rays and Gamma rays?

  can cause the mutation of genes and cancer
• Why does refraction happen?

  refraction is due to the difference in velocity of the waves in different substances
• Which surfaces absorb radiation?

  all surfaces, black is the best absorber
• Which surfaces emit radiation?

  all surfaces, black is the best emitter
• How can radio waves be produced?

  They can be produced by oscillations in electrical circuits
• What happens when radiowaves 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.
• How are electromagnetic waves generated?

  Changes in atoms and their nuclei can result in electromagnetic waves being generated or absorbed over a wide frequency range
• What is B?

  The Normal

  
• What is D?

  Angle of Incidence

  
• What is F?

  Point of incidence

  
• What is E?

  Angle of Reflection

  
• True or false? Higher temperature objects emit less infrared radiation than lower temperature objects?

  False

  
• What are that can be absorbed by water molecules used for?

  Heating Food (Microwave Ovens)
• Microwaves that cannot be absorbed by water molecules are used for?

  Satellite Communications
• What is the device labelled A?

  Split Ring Commutator