Question

Yellow light emitted from sodium lamp has a wavelength of 580nm .Calculate the frequency of the yellow light

Answer 1

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$\sf Frequency = \dfrac{c}{\lambda}$

$\sf 1nm = 10^{-9} \: m$

$\sf 580nm = 580 \times 10^{-9}\: m = 580 \times 10^{-7}\:cm$

$\dashrightarrow$ $\sf v = \dfrac{3.0 \times 10^{8}\: ms^{-1}}{580 \times 10^{-9}\:m}$

$\dashrightarrow$ $\sf 5.17 \times 10^{14}\: s^{-1}$

$\dashrightarrow$ $\sf Wave \:number = \dfrac{1}{\lambda}$

$\dashrightarrow$ $\sf Wave \:number = \dfrac{1}{ 580 \times 10^{-7}\:cm}$

$\gray\dashrightarrow$ $\underline{\boxed{\gray{\sf 1.724 \times 10^{4}\:cm^{-1}}}}$ $\orange\bigstar$

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Answer 2

QUESTION -

Yellow light emitted from sodium lamp has a wavelength of 580nm .Calculate the frequency of the yellow light.

ANSWER -

Yellow light emitted from a sodium lamp has a wavelength (.) of 580 nm

wavelength=580nm =580*10^-9m

we have,

frequency =velocity of light /wavelength

=3*10^8/580*10^-9

=5.17*10^14 per second

wavenumber =1/wavelegth

=1/580*10^-9

=1.724*10^6 m^-1