Flashcards
Nat 5 Telecommunications Flash Cards
Cards in this deck (30)
- 1What waves do?Transfer Energy
- 2What is a wave's medium?The material it travels through
- 3What is the period of a wave?The time taken for one full wavelength to be produced by a source
- 4What is frequency?Number of waves/vibrations per second
- 5What is the zero position?How the medium would be if there was no wave disturbing it
- 6What is the crest of a wave?The highest point/ highest displacement from the zero position (centre line)
- 7What is the trough of a wave?The lowest point/ displacement from the zero position (centre line)
- 8What is the amplitude of a wave?The highest displacement of the wave from the zero position
i.e.
half of the crest + trough - 9What is wavelength?The minimum distance in which the wave repeats itself
- 10What is a longitudinal wave?Longitudinal waves are sound waves
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Medium vibration travels in same way as wave energy - 11What is a transverse wave?Light/electromagnetic
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The medium's vibrations travel at right angles from the direction of the energy - 12What is the Electromagnetic Spectrum?The range of transverse waves ranging from largest to smallest
- 13State the EM spectrumSmallest to Largest
(Gamma, X-rays, Ultraviolet, Visible, Infrared, Microwave, Radio)
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Giant X-ray Unicorns Violently Infect Monkey Rabbits - 14What type of waves can travel through a vacuum?EM waves
- 15What is the speed of light/EM waves in a vacuum/air?300 x 10⁸ ms⁻¹
- 16Can waves be reflected?Yes
- 17What is the normal?A line perpendicular to the surface at the point where the wave touched it
- 18What is the angle of incidence?The angle between the incident ray and the normal line
- 19What is the angle of reflection?The angle between the normal and the reflected wave
- 20What is the incident ray?The ray of light going IN to the reflected point
- 21What is the reflected ray?The ray going away from the point of reflection
- 22What is the Law of Reflection?The angle of incidence is equal to the Angle of reflection
- 23What is a concave reflector?They reflect of the inside of the curve
examples = cosmetic mirrors and telescopes etc. - 24What are convex reflectors?They reflect off the outside of the curve and bring waves together to create a beam
examples = Mirrors in cars to give a wider view - 25How to curved reflectors receive/transmit signals?RECIEVE = They reflect the energy onto a point (focal point) where it is also collected
TRANSMIT = The focal point is a transmitter and diverging waves would create parallel beams away from the reflector - 26What is the principle of reversibility of a ray path?This means that whatever causes the ray to change direction will cause the equivalent to change in the reverse direction
- 27What is Total Internal Reflection (TIR)?When light meets a transparent surface at a large angle of incidence I can then reflect off the this "boundary" between the materials
- 28Can waves be diffracted?Yes
- 29Describe diffractionDiffraction is the way in which a wave bends around obstacles/barriers
When water ripples hit a barrier only some will get past it - 30Why are some diffractions not apparent?Because visible light is so small and although it diffracts we can't perceive by how much as it is so small
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- Flashcards on Nat 5 Telecommunications Flash Cards, created by Matthew Grainger on 26/12/2014.
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- Matthew Grainger
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