Download 9.Wave Properties

Multiple-choice quiz
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Simulation of a transverse wave
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Wavelength of a transverse wave
The wavelength of any wave is the distance between two
matching points on neighbouring waves.
wavelength
wavelength
wavelength
The wavelength is the same whichever two matching points
are used to measure this distance.
The symbol used to represent wavelength is .
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Amplitude of a transverse wave
The amplitude of any wave is the maximum distance a point
moves from its rest position.
amplitude
amplitude
The amplitude of a transverse wave is the height of a peak
or trough from the wave’s rest position of the wave.
The larger the amplitude, greater the energy of the wave.
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Investigating transverse waves
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Frequency of waves – activity
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Simulation of a longitudinal wave
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Transverse or longitudinal waves?
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Total internal reflection – simulation
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What are optical fibres?
Optical fibres are thin strands of
solid glass, about the size of a
human hair.
They are widely used in
communication, medicine,
lighting and as sensors.
The first transatlantic telephone
cable to use optical fibres went
into operation in 1988.
Optical fibres can transmit light
signals at high speed over long
distances and are used in
phone and internet connections.
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Why are optical fibres so important?
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How do optical fibres carry light?
Optical fibres do not have to be straight to carry light and can
even carry light around corners.
This curved Perspex
rod shows how light
travels in an optical
fibre.
Light travels through the Perspex rod, and optical fibres, by a
process called total internal reflection.
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What is total internal reflection?
A ray of light enters the optical fibre.
As the light enters the optical
fibre, it is refracted. This means
that the direction the light is
travelling in changes.
The ray of light hits the wall
of the fibre and is totally
internally reflected when the
angle of incidence is greater
than the critical angle.
The ray of light passes down
the optical fibre by repeated
total internal reflection.
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light enters
optical fibre
light leaves
optical fibre
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What’s in a cable of optical fibres?
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How are optical fibres used in medicine?
Optical fibres can be used by doctors to look inside a
patient’s body without having to cut them open to check that
they are healthy.
The device used for this
purpose is called an
endoscope. It contains a
bundle of optical fibres that
are held together and can
be inserted into the body.
Light is sent down some of
the fibres and the image is
reflected back through the
other fibres.
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Optical fibres – true or false?
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Multiple-choice quiz
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