DP Physics (last assessment 2024)
Question 19M.3.SL.TZ2.12biv
Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.SL.TZ2.12biv |
Level | SL | Paper | 3 | Time zone | TZ2 |
Command term | Outline | Question number | biv | Adapted from | N/A |
biv.
[Maximum mark: 2]
19M.3.SL.TZ2.12biv
The refractive index of a material is the ratio of the speed of light in a vacuum , to the speed of light in the material or .
The speed of light in a vacuum is 2.99792 × 108 m s-1. The following data are available for the refractive indices of the fibre core for two wavelengths of light:
(biv)
A signal consists of a series of pulses. Outline how the length of the fibre optic cable limits the time between transmission of pulses in a practical system.
[2]
Markscheme
longer cables give wider pulses ✔
which overlap/interfere if T too small/f too high ✔
OWTTE
Examiners report
Most candidates did not mention the fact that if the time between pulses was too small then the pulses would overlap for longer fibres.
