Optical fibres are used to transmit digital signals using infrared radiation. The average refractive index of the fibres is 1.60.
Which row in the table below correctly describes a digital signal and gives the speed of this infrared radiation in the fibres (taking the speed of light in vacuum to be c=3.0×108 m/sc = 3.0 \times 10^8 \text{ m/s}c=3.0×108 m/s)?
| Description of a digital signal | Speed of infrared radiation in the fibres (m/s\text{m/s}m/s) | |
|---|---|---|
| A | A signal consisting of only two values | 1.9 × 108 |
| B | A signal consisting of only two values | 4.8 × 108 |
| C | A signal consisting of a continuously varying range of values | 1.9 × 108 |
| D | A signal consisting of a continuously varying range of values | 4.8 × 108 |
Row A
Row B
Row C
Row D
100 exam-style questions on CIE IGCSE Physics 3.2.2 Refraction of light. Each one has a worked solution and a mark scheme showing where the marks go.