Polarisation and invisible radiations
Answers are for parents and teachers.
1
I₀ = 64 (arbitrary units), α = 45°. What is I?
32
2
Natural light has intensity 200. What is the intensity after two polarisers with parallel axes?
100
3
What is the frequency of IR radiation with λ = 10 μm in units of 10¹³ Hz?
3
4
Why do polaroid glasses reduce glare from water or a road surface?
The reflected light is largely polarised in one direction; the glasses' axis is perpendicular to it, so they block it.
5
Why is an X-ray examination done only when necessary and in limited amounts?
X-rays can damage living cells; reducing the dose reduces the risk.