Visible + UV light

what has the longest wavelength in visible light?

red

what has the shortest wavelength in visible light

violet

How are real images formed?

By the convergence of actual light rays

a convex mirror forms a _______ image behind the mirror

virtual

a concave mirror can form a ____ image if the object is _______ ______ than the focal point

real , further away

how is visible light used in communication

using optical fibres - they are thin glass or plastic fibres that are able to transmit pulses of light over long distances because light is reflected every time it hits the surface and so it ends up bouncing back and forth until it emerges at the other end of the fibre where it can be interpreted

It uses : total internal reflection and it's specular reflection

UV light is emitted from the _____

sun

what are the use of UV radiation

- security eg. security pens

- fluorescent lights : generate UV radiation, aborbed by a layer of phosphorus then re emits the energy as visible light

- tanning beds

- sterilising water