Answer :
Answer:
[tex]\lambda_2 = 573.3 nm[/tex]
Explanation:
As we know that the position of maximum intensity on the screen is given as
[tex]y = \frac{N\lambda L}{d}[/tex]
here we know that
[tex]\lambda[/tex] = wavelength
L = distance of the screen
d = distance between two slits
now we know that the position of 8th maximum intensity is same as that of 9th maximum on the screen
so we have
[tex]\frac{N_1\lambda_1 L}{d} = \frac{N_2 \lambda_2 L}{d}[/tex]
so here we have
[tex]8 (645 nm) = 9 \lambda_2[/tex]
[tex]\lambda_2 = 573.3 nm[/tex]