Question

Early investigators (including Thomas Young) measured the thickness of wool fibers using diffraction. One early instrument used a collimated beam of 560 nm light to produce a diffraction pattern on a screen placed 30 cm from a single wool fiber.
part a: If the fiber's diameter was 18 μm, what was the width of the central maximum on the screen?

Answer 1

Answer:

$w= 1.867\times10^{-2}$

Explanation:

Given:

fibers diameter d= 18 μm

distance of the screen D= 30 cm

wavelength λ= 560 nm

we know that fringe width

$w=\frac{2\lambda D}{d}$

putting values we get

$w=\frac{2\times560\times10^{-9}\times0.3}{18\times10^{-6}$

$w= 1.867\times10^{-2}$