Electromagnetic Waves

• What type of spectrum do electromagnetic waves form? 

  A continous spectrum. 
• Order the types of electromagnetic radiation.

  Radio waves

  Microwaves

  Infrared

  Visible Light

  Ultraviolet

  X-Rays

  Gamma Rays
• How do speeds of EM radiation differ in a vacuum and air? 

  All travel at the same speed In a vacuum and in air.
• What property of waves in different mediums cause refraction?

  Velocity

  Wave speed is slower in denser material, causing refraction    
• In which direction do waves refract when entering entering a denser medium?

  Towards the normal

  Angle of refraction is less then angle of incidence
• Health effects of ultraviolet waves:

  Skin to age prematurely

  Increase risk of skin cancer   
• Health effects of X-rays and Gamma rays:

  They are ionising so can lead to gene mutation

  They lead to increased risk of developing various cancers. 
• Uses of infrared radiation:

  Electrical heaters

  Cooking food

  Infrared cameras
• Uses of microwave radiation.

  Satellite communication

  Cooking food   
• Two uses of radio waves

  Television transmission

  Radio transmission