A science exhibition lists several everyday applications of electromagnetic waves, but does not mention which part of the spectrum is involved.
(i) For each of the following applications, identify the most appropriate region of the electromagnetic spectrum and give one reason for your choice:
(a) Remote control of a television set
(b) Satellite television down-link reception
(c) Sterilisation of packaged medical syringes
(d) Night-vision imaging
(ii) Satellite television commonly uses a down-link frequency of 12GHz. Calculate the corresponding wavelength in free space.
(iii) Optical fibre communication often operates at a wavelength of 1.55μm. Identify the spectral region to which this wavelength belongs and calculate its frequency.