Waves and optics

Question 1

What is a wave?

Answer 1

A disturbance in a medium which transfers energy without transferring mass.

Question 2

What is the amplitude, wavelength, and frequency of a wave?

Answer 2

Amplitude - The maximum displacement of a particle from its equilibrium position.

Wavelength - The minimum distance between two points on the wave that are in phase.

Frequency - No. of complete waves the pass a point per second

Question 3

What is the phase difference for two points on a wave that are:
- in phase?
- in antiphase?
- out of phase?

Answer 3

Points seperated by an integer multiple of wavelengths (λ, 2λ, 3λ, etc) will be in phase.
Δø = 0, 2π, 4π, 6π, etc.

Points seperated by an odd integer number of half wavelengths (λ/2, 3λ/2, 5λ/2, etc) will be in antiphase.
Δø = π, 3π, 5π, etc.

Any other Δø is described as being “out of phase”.

Question 4

What is the equation for the phase difference between two points on a progressive wave?

Question 5

What are the wave equations? (3)

Question 6

How do you calculate phase differences?

Question 7

Describe the nature of a longitudinal wave (give 2 examples)

Question 8

Describe the nature of a transverse wave (give 2 examples)

Question 9

What is the speed of an electromagnetic wave in a vacuum?

Question 10

What does it mean for a wave to be polarised, and what type of waves can be polarised?

Question 11

What are some applications of polarisers?

Question 12

What is the principle of superposition?

Question 13

What is a stationary wave and how are they formed?

Question 14

What is a node and why is it formed?

Question 15

What is an antinode and why is it formed?

Question 16

How do the wavelengths of the harmonics on a string compare to the length of a string?

Question 17

How can the frequencies of the harmonics on a string be calculated?

Question 18

What are the differences between progressive and stationary waves?

Question 19

What is the first harmonic equation?

Question 20

What factors of the string determine the frequency of its first harmonic?

Question 21

What is the range of visible wavelengths and in what order are the colours found?

Question 22

What does it mean for a light source to be monochromatic?

Question 23

What does it mean for two light sources to be coherent?

Question 24

What is the relationship between path difference and phase difference?

Question 25

What assumptions are made when deriving the double slit formula?

Question 26

What is the double slit formula?

Question 27

What is the path difference equation?

Question 28

What is diffraction?

Question 29

What is the pattern observed when monochromatic light is shone through a single slit?

Question 30

What is the pattern observed when white light is shone through a single slit?

Question 31

How does the width of the central maximum vary with the slit width?

Question 32

How does single slit diffraction affect the pattern from a double slit experiment?

Question 33

What is the relationship between the grating spacing and the number of lines per metre?

Question 34

What is the equation for the highest order maximum seen?

Question 35

What are some uses of diffraction gratings?

Question 36

What is the diffraction grating formula?

Question 37

What is refraction?

Question 38

What is the refractive index of a material and how is it calculated?

Question 39

Name some of the refractive indices you should expect for air, water, glass and diamond (TAZARLORD REFERENCE?)

Question 40

Which angle is used in Snell’s Law calculations?

Question 41

What is total internal reflection (TIR)?

Question 42

What is the critical angle?

Question 43

What are the two components of a fibre optic cable and their functions?

Question 44

What is material dispersion, why does it occur and how can it be mitigated?

Question 45

What is modal dispersion, why does it occur and how can its effects be mitigated?