Answer:
L= 27.42m
Explanation:
We have the variables
[tex]D=4.6*10^{-3}m[/tex]
[tex]d= 4*10^{-3}m[/tex]
[tex]\lambda = 550*10^{-9}m[/tex]
Use the relation,
[tex]L=\frac{D}{\theta_R} = \frac{D_d}{1.22\lambda}[/tex]
[tex]L= \frac{(4.6*10^{-3}m)(4*10^{-3}m)}{1.22(550*10^{-9}m)}[/tex]
[tex]L= 27.42m[/tex]