Respuesta :
Answer
given,
wavelength (λ) = 650 nm
angle = 5°
using bragg's law
[tex]sin \theta = \dfrac{n \lambda}{d}[/tex]
[tex]d= \dfrac{n \lambda}{sin \theta}[/tex]
[tex]d= \dfrac{1 \times 650 \times 10^{-9}\ m}{sin5^0}[/tex]
d = 7.46 x 10⁻⁴ cm
number of slits per centimeter
= [tex]\dfrac{1}{d}\\\Rightarrow \dfrac{1}{7.46\times 10^{-4}}\\\Rightarrow 1340 split per centimeter.[/tex]
b) wavelength of two rays 650 nm and 420 nm
[tex] d = \dfrac{1}{5000}[/tex]
d = 2 x 10⁻6 m
we now,
[tex]sin \theta = \dfrac{n \lambda}{d}[/tex]
for 650 nm
[tex]sin \theta = \dfrac{2\times 650\times 10^{-9}}{2\times 10^{-6}}[/tex]
[tex]\theta =sin^{-1}(0.65)[/tex]
θ = 40.54°
for 450 nm
[tex]sin \theta = \dfrac{2\times 450\times 10^{-9}}{2\times 10^{-6}}[/tex]
[tex]\theta =sin^{-1}(0.45)[/tex]
θ = 24.83°
now, difference
|θ_{650} -θ_{420}| =40.54°-24.83°
|θ_{650} -θ_{420}| =19.71°
