WAVES

Question 1

Amplitude

Answer 1

Maximum displacement of a wave from equillibrium

Question 2

Antinode

Answer 2

Point of maximum displacement

Question 3

Cladding

Answer 3

A protective layer on an optical fibre to improve tensile strength, prevent scracthing and cross-talk.

Question 4

Coherence

Answer 4

Waves are coherent if they have the same freuqency and wavelength, and a constant phase difference.

Question 5

Diffraction

Answer 5

The spreading of waves as they pass through a gap of similar magnitude to their wavelength

Question 6

Interference

Answer 6

Name given to the superposition of two waves when they meet.

Question 7

Laser

Answer 7

A monochromatic light source that produces a collimated and coherent beam.

Question 8

Material dispersion

Answer 8

Different wavelengths of light travelling at different speeds.

Question 9

Modal dispersion

Answer 9

Fibre is too broad

Question 10

Node

Answer 10

Point of minimum displacement

Question 11

Path difference

Answer 11

A measure of how far ahead one wave is compared to another, expressed in terms of wavelength

Question 12

Phase

Answer 12

A measure of how far through the waves cycle a given point on the wave is

Question 13

Polarisation

Answer 13

Restricting the oscillations of a wave to a single dimension

Question 14

Refractive index

Answer 14

Ratio of speed in a vacuum to speed in the given material

Question 15

Total internal reflection (TIR)

Answer 15

When full reflection of the wave occurs at the inside boundaries, when travelling into a material of lower refractive index and at an angle greater than the critical angle.