Flashcards
Waves
Flashcards do conjunto (20)
- 1What is a progressive wave?An oscillation or vibration that travels through a substance or space transferring energy.
- 2What is the amplitude of a wave?The maximum displacement from the undisturbed position.
- 3What is the frequency of a wave?The number pf cycles per second, measured in Hertz.
- 4What does it mean for particles in a wave to move 'in phase'?They are moving in the same direction with the same speed as each other. They also have the same displacement from their mean position.
- 5What is the difference between longitudinal and transverse waves?Particles vibrate parallel to the direction that energy travels in for longitudinal waves. Particles vibrate perpendicular to the direction that energy travels in for transverse waves.
- 6What are the properties of electromagnetic waves?They are transverse waves that travel at the speed of light.
- 7What are compressions and rarefactions in sound waves?They are the regions of high pressure and lower pressure respectively.
- 8State the order of the electromagnetic spectrum from shortest wavelength to longest wavelength.Gamma rays
X-rays
UV
Visible
IR
Microwaves
Radio waves - 9Why do we use radio waves to transmit TV and radio programmes instead of other wavelengths?Radio waves aren't absorbed by the atmosphere and won't diffract as much.
- 10What is a polarised wave?The oscillations of the wave are confined to one plane.
- 11Name two polarisation applications.Polarising sunglasses.
Outdoor television and FM radio aerials. - 12What is refraction?The change in direction at a boundary when a wave travels from one medium to another.
- 13What is the refractive index?The ratio of a wave's speed between two materials.
- 14What is approximately the refractive index of air?One.
- 15What is total internal reflection?The complete reflection of a wave at a boundary within a material that has a higher refractive index than its surroundings.
- 16What is the critical angle?The angle of refraction for which the angle of incidence is 90 degrees.
- 17What is an optical fibre?A thin glass or plastic fibre that transmits light.
- 18What is material dispersion and what does it cause?The spreading of a signal caused by the variation of refractive index with wavelength. It causes pulse broadening.
- 19What is modal dispersion?The spreading of a signal caused by rays taking slightly different paths in the fibre.
- 20What is absorption?Energy from a signal is absorbed by the optical fibre in which it travels.
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- A level Physics (Physics Flash Cards) FlashCards sobre Waves, criado por Sam Bronsdon em 01-06-2017.
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- Sam Bronsdon
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