Electromagnetic radiation and optical telescopes
Answers are for parents and teachers.
1
For λ = 750 nm what is ν in THz? (300,000 : 750 = 400)
400
2
For λ = 500 nm what is ν in THz? (300,000 : 500)
600
3
Write one advantage each of a reflector and a refractor.
Reflector: large mirror, no colour fringes; refractor: sealed tube, little re-adjustment.
4
Why is an infrared telescope such as Webb kept very cold behind a large sunshield?
It must stay cold so its own heat does not swamp the faint infrared signals.
5
When were gravitational waves first detected and with which instrument?
In 2015 with LIGO.