Polarisation Flashcards
What are the uses of polarisation
polaroid sunglasses to reduce glare from snow
polarised light from space
polarised seismic waves - learn about earth structure
What can be polarised
mechanical or em waves
What is the only wave to be polarised with a polariser
only transverse
What is the direction of polarisation of any EM wave defined by?
Electric field oscillation
With microwaves if you have vertical metal rods and send microwaves of different directions which waves travel through
Only horizontal i.e perpendicular to rods
transmission axis drawn horizontally to show what electric field is transmitted
How do we polarise visible light
similar to microwave but rods are closer together
What are crossed polaroids
merging two polaroids one with hoirzontal and one with vertical rods to completely wipe light
To align aerials what must you do
keep rods and waves in same alignment so absorbed/recieved correctly
