Question

calculate the wavelength, frequency, and wavenumber of a light wave whose period is 2×10^-10 s. class11​

Answer 1

Answer:-

• Period of light=2×10$^{-10}$s
• Frequency=v=?
• Wavelength=$\lambda$=?
• Wavenumber=$\sf \overline{v}$

We know that

$\boxed{\sf Frequency_{(\nu)}=\dfrac{1}{Period}}$

$\\ \rm\longmapsto \nu=\dfrac{1}{2\times 10^{-10}}$

$\\ \rm\longmapsto \nu=5\times 10^9/s$

$\\ \underline{\boxed{\bf{\therefore \nu=5\times 10^9/s.}}}$

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We know that

$\boxed{\sf Wavelength_{(\lambda)}=\dfrac{C}{V}}$

$\\ \rm\longmapsto \lambda=\dfrac{3\times 10^8m/s}{5\times 10^9/s}$

$\\ \rm\longmapsto \lambda=6\times 10^{-2}m$

$\\ \underline{\boxed{\bf{\therefore \lambda=6\times 10^{-2}m.}}}$

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We know that

$\boxed{\sf Wavenumber_{(\overline{\nu})}=\dfrac{1}{\lambda}}$

$\\ \rm\longmapsto \overline{\nu}=\dfrac{1}{6\times 10^{-2}m}$

$\\ \rm\longmapsto \overline{\nu}=16.6/m$

$\\ \underline{\boxed{\bf{\therefore \overline{\nu}=16.6/m.}}}$