Flashcards
Waves flashcards
Cards in this deck (30)
- 1Refractive index of air?1
- 2Refractive index of water?1.3
- 3Refractive index of glass?1.5
- 42 uses of optical fibres?1) for medical imaging (like endoscopes)
2) for communications - 5What is the issue sometimes with endoscopes?They can have crosstalk sometimes between the wires and the wires can change or get crossed (not be coherent)
- 6Draw a labelled diagram of an optical fibre and what has higher/lower refractive indexes.
- 7What is modal dispersion?the spreading (over time) of a signal travelling down the fibre- when light takes 2 different paths
- 8What is pulse broadening?when 2 separate pulses of light can merge with each other
- 9What is spectral/chromatic dispersion and how do you stop it?different frequencies of light travel at different speeds so monochromatic or infrared used
- 10How do you prevent modal dispersion?Make the core narrower
- 11List 5 reasons for the cladding1) to protect the core from scratches and therefor light leakage
2) to prevent crossover or loss of information
3) to increase the critical angle and reduce pulse broadening
3) rays with a smaller angle of incidence are refracted out
5) increases the rate of data transfer - 12Draw polarised light diagram
- 13Draw a stationary wave
- 14What happens to the energy of a stationary wave?It stays between 2 nodes
- 15How is a stationary wave formed?formed by the superposition of 2 identical but opposite progressive waves
- 16which direction is the energy transferred in a progressive wave?in the direction of the propagation of the wave
- 17What is the phase difference of 2 particles in a progressive wave?2pid/lambda where d is the distance between their equilibrium positions
- 18Open pipe harmonics: where is the antinode?at the ends
- 19Closed pipe harmincs: where is the antinode?in the middle
- 20What do T and mu stand for in the waves on a string equation?T- tension in the string
mu- mass per unit length - 21What is the first harmonic in relation to the wavelength? and draw
- 22What are the 2 conditions for interference?the waves must be
1) the same frequency
2) have a constant path difference
(be coherent) - 23What is path difference?the difference in the distances travelled
- 24what are the formulas for path and phase difference?path difference = n x wavelength
phase difference = n2pi - 25Describe the interference pattern from 1 slit diffraction1) central fringe 2x the width of the others
2) the peak intensity decreases form the centre
3) outer fringes are the same width
4) outer fringes are much less intense - 26Describe interference pattern from 2 slits (white light)1) central fringe is white
2) all other fringes show the full spectrum
3) blue inside of the fringe, red outside
4) dark fringes narrower - 27what happens to the interference pattern of a double slit if the wavelength increases?1) the width of the slits increase
2) the slits are further apart - 28what happens to the interference pattern if the slit gets wider?The peaks get narrower in width
- 29Draw the formula for path difference diagram
- 30Draw 3 diagrams for total internal reflection, stating when it happens in reference to the critical angle.
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- A level Physics (Waves) Flashcards on Waves flashcards, created by Naomi Meeks on 30/01/2023.
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- Naomi Meeks
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