 | Term | Definition |
| |
Wave |
Transmitter of energy without the movement of particles from place to place. The vibration of particles or energy fields is involved. |
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Transverse wave |
Waves involving the vibration of particles perpendicular to the direction of energy transfer. |
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Compression wave |
Waves involving the vibration of particles in the same direction as energy transfer. |
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Longitudinal wave |
Compression wave. |
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Medium |
Material through which a wave moves. |
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Compression |
Region in which the particles are closer than when not disturbed by a wave. |
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Rarefaction |
Region in which the particles are father apart than when not disturbed by a wave. |
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Frequency |
Number of vibrations in one second, or the number of wavelengths passing in one second. |
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Hertz |
Unit of frequency; its abbreviation is Hz. One hertz is equal to one vibration every second. |
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Pitch |
Highness or lowness of a sound. The pitch that you hear depends on the frequency of the vibrating air. |
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Wave length |
Distance between two neighboring crests or troughs of a wave. This is the distance between two particles vibrating in step. |
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Amplitude |
Maximum distance that a particle moves away from its undisturbed position. |
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Sonar |
Use of reflected sound waves to locate objects under water (Sound Navigation And Ranging) |
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Echolocation |
Use of sound to locate objects by detecting echoes. |
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Ultrasound |
Sound with frequencies too high for humans to hear. |
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Infra-red radiation |
Invisible radiation emitted by all warm objects. You feel infra-red radiation as heat. |
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Electromagnetic spectrum |
Complete range of wavelengths of energy radiated as electric and magnetic fields. |
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Radio Waves |
Low energy electromagnetic waves with a much lower frequency and longer wavelength than visible light. |
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Visible light |
Very small part of the electromagnetic spectrum to which our eyes are sensitive. |
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Ultra violet radiation |
Invisible radiation similar to light but with a slightly higher frequency and more energy. |
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X-rays |
High energy electromagnetic waves that can be transmitted through solids and provide information about their structure. |
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Gamma rays |
High energy electromagnetic radiation produced during nuclear reactions. |
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Electromagnetic waves |
Electromagnetic energy that is transmitted as a moving electric and magnetic fields. There are many different types of electromagnetic energy. E.g. light, microwaves, radio waves. |
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Magnetic field |
Area where a magnetic force is experienced by another magnet. The direction of the magnetic force is shown by drawing field lines; the size of the force is shown by how close together the lines are. |
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Electromagnet |
Magnet formed by wrapping a coil of wire around an iron core. When electricity passes through the coil, the iron core becomes an electromagnet. |
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Solenoid |
Coil of wire able to pass a current. |
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Synchrotron |
A building-sized device that uses electrons accelerated to near the speed of light to produce intense electromagnetic radiation. This is used to produce data that can describe objects as small as a single molecule. |
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North Pole |
End of the magnet that when free to rotate, points to the north pole of the Earth. The magnetic forces are strongest at the poles of a magnet. |
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South Pole |
End of a magnet opposite to the north pole and attract to the north pole of another magnet. |
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Permanent Magnet |
Magnet that retains its magnetic effect for many years. |
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Temporary magnet |
Magnet that stays magnetic while it touches a permanent magnet, or one that is magnetic for a very short time. |
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Voice coil |
Coil of a wire in a loudspeaker that vibrates at the frequency of the electrical signal. This frequency matches the frequency of the sound produced by the cone. |
| |
Diaphragm |
Cone of a loudspeaker that vibrates to produce a sound wave. |
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