Uses and Dangers of EM Waves

• What type of waves can be produced by oscillations in an electrical circuit?

  Radio waves
• How can radio waves create an alternating current in a circuit?

  When radio waves are absorbed, they can induce oscillations in a circuit with the same frequency as the waves themselves.
• Where do gamma rays originate from?

  They originate from changes in the nuclei of atoms.
• What health effects can ultraviolet waves cause?

  They can cause the skin to age prematurely, they can increase the risk of developing skin cancer.
• What health effects can cause X-rays and Gamma rays cause?

  They are ionising radiation so can cause mutations in genes. They can lead to increased risk of developing various cancers.
• What health effects can infrared rays cause?

  Burns to skin and tissue
• How does electromagnetic radiation affect electron arrangement in atoms?

  Absorption or emission of electromagnetic radiation can cause electron arrangement too change. (It can remove electrons from the atom or move electrons further from the nucleus).
• What are the effects of body cells absorbing radiation?

  Large amounts can damage cells, smaller amount can cause mutations, causing cells to divide rapidly, which can lead to cancer.
• State a use of radio waves

  Communications, because radio waves are long wavelength and can travel long distances without losing quality.
• State a use of microwaves

  Cooking, as microwaves are absorbed by and heat fat/water in foods.
• State a use of infrared radiation

  Cooking food (as it transfers thermal energy), infrared cameras, short range communication.
• State a use of visible light

  Illuminating (seeing) and fibre optics, as they reflect best in glass (other waves have wavelengths that are too long/short).
• State a use of UV radiation

  Sterilisation, as it kills bacteria, energy efficient lamps, as it radiates low heat but high energy, and sun tanning.
• State a use of a X-rays

  Medical imaging and treatment, because they are high energy and can easily penetrate body tissues.
• State a use of gamma rays

  Medical treatments, such as radiotherapy in the treatment of cancer.
• Which waves of the EM spectrum are the most dangerous and why?

  Gamma and X-rays, as they have the highest energy.