physics unit 7 (total internal reflection of waves)

what happens a the critical angle

Lights bends along the boundary

what happens when light is increased above critical angle

The light will reflect, this is called total it neral reflection

what 2 things must happen for total internal reflection

1. The light must travel from a higher optical density towards a lower optical density. Eg glass into air

2. The angle between the normal and the ray of light must be greater than the critical angle

what is total internal reflection used in

Optical fibers

describe how total internal reflection is used in optical fibers

Light is sent along a glass tube reflecting from the side of the tube until it reaches the end. This is very useful to sen information quickly over long distances

how do endoscope use total internal reflection

To investigate specific area of the body. Light is sent into the body through and optical fiber and reflected back along another optical fiber to a camera located outside the body

what do endoscope do

Investitage specific areas of the body in detail

And are less harmful as no ionising radation is used

what are ct scans used for

To investage the body.They use x-rays to generate more overall images of the body and are in 3d

what do ct scans do

They give a more overall picture but pose a higher risk due to the x-rays having ionising radation

list the features of a satellite

Uses microwaves

Faster wave speed(300 000 000m/s)

Larger distances-longer delay

Can communicate anywhere

list the features of an optical fiber

Uses infrared

Slower wave speed(200,000,000m/s)

Shorter distance=smaller delay

Needs a connection to enter the fiber

how do satellites send signals to eachother

Through a base station, satellites cannot send signals directly to eachother