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| Wavelength, Frequency and Time Period |
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| Wavelength, frequency and time period describe a wave. Now let us define these terms. |
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| Wavelength is defined as the distance between the two nearest points on the wave or it can be defined as the distance between two consecutive crests or troughs in the case of a transverse wave or it is the distance between two consecutive compressions or rarefactions. |
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| Wavelength is denoted by l (pronounced as lambda). Its unit is meter. Angstrom is also an unit of wavelength. |
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1 Angstrom
 = 10-8 cm. |
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| Time period of a wave is the time taken by a vibrating particle to make one complete vibration or it can be also defined as the time taken by a wave to move a distance equal to its wavelength. It is denoted by T. Its unit is second. |
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| Frequency is the number of vibrations completed by a particle in one second or it is also defined as the number of waves passing through a point in one second. It is denoted by u (pronounced as new). Its unit is hertz (Hz). |
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| Let u be the frequency of a wave. That is, the number of vibrations completed by a particle in one second is u. |
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 Time taken to complete u vibrations = 1 second. |
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But time taken to complete one vibration is defined as the time period
of the wave  |
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| Wave velocity is defined as the distance traveled by the wave in one second. |
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Or Wave velocity = Wavelength  frequency. |
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