In young’s experiment the wavelength of red light is $7.8 imes 10^{- 5}\ $cm and that of blue light $5.2 imes 10^{- 2}$ cm. The value of $n\ $for which $(n + 1)$th blue bright band coincides with $n^{th}$red band is

Question

In young’s experiment the wavelength of red light is $7.8 	imes 10^{- 5}\ $cm and that of blue light $5.2 	imes 10^{- 2}$ cm. The value of $n\ $for which $(n + 1)$th blue bright band coincides with $n^{th}$red band is

Dr. Abubacker · Accepted Answer

(c) $x = (n + 1)\lambda_{b} = n\lambda_{r}$
$\frac{n + 1}{n} = \frac{\lambda_{r}}{\lambda_{b}} = \frac{7.8 	imes 10^{- 5}}{5.2 	imes 10^{- 5}} = \frac{3}{2}$
$1 + \frac{1}{b} = \frac{3}{2}$
$n = 2$

Q. In young’s experiment the wavelength of red light is $7.8 \times 10^{- 5}\ $cm and that of blue light $5.2 \times 10^{- 2}$ cm. The value of $n\ $for which $(n + 1)$th blue bright band coincides with $n^{th}$red band is

Explanation

Reviewed by Dr. Abubacker

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