| A | B |
|---|
| diffraction | waves spread out when they go through a hole |
| refraction | waves change direction when they go into different density materials |
| wavelength | measured in metres - length of one wave |
| trough | bottom of a wave |
| crest | top of a wave |
| laser | an intense beam of light at one frequency |
| seismic | earthquake waves |
| primary | another name for p waves |
| secondary | another name for s waves |
| transverse | examples are light waves and radio waves. |
| longitudinal | examples are sound waves and p waves |
| ultraviolet | these waves can cause sunburn |
| infrared | these waves are associated with global warming |
| swaves | travel only through solids in the earth |
| wirelesstechnology | radios, mobile phones and laptops are examples of... |
| digital | these kind of signals don't get interference |
| burglaralarm | a use for infrared sensors |
| multiplexing | optical fibres can carry lots of signals at the same time. This is called... |
| laser | CD players work by using this type of radiation |
| ozonelayer | protects us from harmful UV radiation |
