Answer:
[tex]w= 1.867\times10^{-2}[/tex]
Explanation:
Given:
fibers diameter d= 18 μm
distance of the screen D= 30 cm
wavelength λ= 560 nm
we know that fringe width
[tex]w=\frac{2\lambda D}{d}[/tex]
putting values we get
[tex]w=\frac{2\times560\times10^{-9}\times0.3}{18\times10^{-6}[/tex]
[tex]w= 1.867\times10^{-2}[/tex]