Way to detect :
1. Infrared radiations : It we move a thermometer with blackend bulb from violet to red end of a visible spectrum, there is a slight rise in temperature and if the bulb is moved in the region beyond red, there is sudden rise in temperature, this proves that the region beyond red is not visible and produces heating effect is Infrared region.
2. Ultraviolet radiations : When a silver chloride (Ag Cl) paper is placed in the region beyond violet, the paper first turns violet, then BROWN and finally black. This proves that there is a region beyond violet which is invisible and produces. Strong chemical effect in silver chloride is known as Ultraviolet regions.
