Which one of the following types of waves are used in a night vision apparatus?
- ARadio waves
- BMicrowaves
- CInfra-red wavesCorrect
- DNone of the above
Explanation
Infrared waves are used in night vision apparatus because they allow for the detection of heat signatures. Night vision devices work by either amplifying small amounts of available light or by detecting infrared radiation emitted as heat by objects and living beings. Since all objects above absolute zero emit infrared energy, these waves make it possible to see in total darkness where visible light is absent. Radio waves and microwaves are not suitable for this purpose as they are typically used for communication and radar rather than thermal imaging.
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