Question 18M.3.SL.TZ1.9b
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.3.SL.TZ1.9b |
| Level | SL | Paper | 3 | Time zone | TZ1 |
| Command term | Outline | Question number | b | Adapted from | N/A |
A ray of light travelling in an optic fibre undergoes total internal reflection at point P.
The refractive index of the core is 1.56 and that of the cladding 1.34.
The use of optical fibres has led to a revolution in communications across the globe. Outline two advantages of optical fibres over electrical conductors for the purpose of data transfer.
[2]
optic fibres are not susceptible to earthing problems
optic fibres are very thin and so do not require the physical space of electrical cables
optic fibres offer greater security as the lines cannot be tapped
optic fibres are not affected by external electric/magnetic fields/interference
optic fibres have lower attenuation than electrical conductors/require less energy
the bandwidth of an optic fibre is large and so it can carry many communications at once/in a shorter time interval/faster data transfer
[2 marks]
