Correct Answer - Option 2 : 2 Ȧ
Concept:
Bragg’s Law states that when an X-ray beam are allowed to scatter through a crystalline surface, its angle of incidence θ will reflect with some angle of scattering θ. And when the path difference d is equal to a whole number n, of wavelength.
It can be represented as
2dsinθ =nλ
Calculation:
Given:
n = 2, d = 4 Ȧ, θ = 30°
nλ = 2d sin θ
\(λ = \frac{{2d\sin θ }}{n}\)
\(= \frac{{2\; \times \;4\dot A\; \times \;\frac{1}{2}}}{2} = 2\dot A\)
